of Who’s Afraid of Huawei? Understanding the 5G Security Concerns By feedproxy.google.com Published On :: Fri, 06 Sep 2019 09:55:03 +0000 9 September 2019 Emily Taylor Associate Fellow, International Security Programme @etaylaw LinkedIn Emily Taylor examines the controversy around the Chinese tech giant’s mobile broadband equipment and the different approaches taken by Western countries. 2019-09-06-Huawei.jpg Huawei's Ox Horn campus in Dongguan, China. Photo: Getty Images. As countries move towards the fifth generation of mobile broadband, 5G, the United States has been loudly calling out Huawei as a security threat. It has employed alarmist rhetoric and threatened to limit trade and intelligence sharing with close allies that use Huawei in their 5G infrastructure.While some countries such as Australia have adopted a hard line against Huawei, others like the UK have been more circumspect, arguing that the risks of using the firm’s technology can be mitigated without forgoing the benefits.So, who is right, and why have these close allies taken such different approaches?The risksLong-standing concerns relating to Huawei are plausible. There are credible allegations that it has benefitted from stolen intellectual property, and that it could not thrive without a close relationship with the Chinese state.Huawei hotly denies allegations that users are at risk of its technology being used for state espionage, and says it would resist any order to share information with the Chinese government. But there are questions over whether it could really resist China’s stringent domestic legislation, which compels companies to share data with the government. And given China’s track record of using cyberattacks to conduct intellectual property theft, there may be added risks of embedding a Chinese provider into critical communications infrastructure.In addition, China’s rise as a global technological superpower has been boosted by the flow of financial capital through government subsidies, venture and private equity, which reveal murky boundaries between the state and private sector for domestic darlings. Meanwhile, the Belt and Road initiative has seen generous investment by China in technology infrastructure across Africa, South America and Asia.There’s no such thing as a free lunch or a free network – as Sri Lanka discovered when China assumed shares in a strategic port in return for debt forgiveness; or Mexico when a 1% interest loan for its 4G network came on the condition that 80% of the funding was spent with Huawei.Aside from intelligence and geopolitical concerns, the quality of Huawei’s products represents a significant cyber risk, one that has received less attention than it deserves.On top of that, 5G by itself will significantly increase the threat landscape from a cybersecurity perspective. The network layer will be more intelligent and adaptable through the use of software and cloud services. The number of network antennae will increase by a factor of 20, and many will be poorly secured ‘things’; there is no need for a backdoor if you have any number of ‘bug doors’.Finally, the US is threatening to limit intelligence sharing with its closest allies if they adopt Huawei. So why would any country even consider using Huawei in their 5G infrastructure?Different situationsThe truth is that not every country is free to manoeuvre; 5G technology will sit on top of existing mobile infrastructure.Australia and the US can afford to take a hard line: their national infrastructure has been largely Huawei-free since 2012. However, the Chinese firm is deeply embedded in other countries’ existing structures – for example, in the UK, Huawei has provided telecommunications infrastructure since 2005. Even if the UK decided tomorrow to ditch Huawei, it cannot just rip up existing 4G infrastructure. To do so would cost a fortune, risk years of delay in the adoption of 5G and limit competition in 5G provisioning.As a result, the UK has adopted a pragmatic approach resulting from years of oversight and analysis of Huawei equipment, during which it has never found evidence of malicious Chinese state cyber activity through Huawei.At the heart of this process is the Huawei Cyber Security Evaluation Centre, which was founded in 2010 as a confidence-building measure. Originally criticized for ‘effectively policing itself’, as it was run and staffed entirely by Huawei, the governance has now been strengthened, with the National Cyber Security Centre chairing its oversight board.The board’s 2019 report makes grim reading, highlighting ‘serious and system defects in Huawei’s software engineering and cyber security competence’. But it does not accuse the company of serving as a platform for state-sponsored surveillance.Similar evidence-based policy approaches are emerging in other countries like Norway and Italy. They offer flexibility for governments, for example by limiting access to some contract competition through legitimate and transparent means, such as security reviews during procurement. The approaches also raise security concerns (both national and cyber) to a primary issue when awarding contracts – something that was not always done in the past, when price was the key driver.The UK is also stressing the need to manage risk and increase vendor diversity in the ecosystem to avoid single points of failure. A further approach that is beginning to emerge is to draw a line between network ‘core’ and ‘periphery’ components, excluding some providers from the more sensitive ‘core’. The limited rollouts of 5G in the UK so far have adopted multi-provider strategies, and only one has reportedly not included Huawei kit.Managing the risks to cyber security and national security will become more complex in a 5G environment. In global supply chains, bans based on the nationality of the provider offer little assurance. For countries that have already committed to Huawei in the past, and who may not wish to be drawn into an outright trade war with China, these moderate approaches offer a potential way forward. Full Article
of POSTPONED: What Impact of Sovereignty in the Internet? By feedproxy.google.com Published On :: Mon, 02 Mar 2020 11:15:01 +0000 Research Event 26 March 2020 - 6:00pm to 7:00pm Chatham House Event participants Konstantinos Komaitis, Senior Director, Policy Development & Strategy, Internet SocietyGregory Asmolov, Leverhulme Early Career Fellow Russia Institute, King’s College LondonFurther speakers to be announced.Chair: Joyce Hakmeh, Senior Research Fellow, International Security Programme, Chatham House and Co-Editor of the Journal of Cyber Policy. Several governments have been moving towards a stronger sovereignty narrative when it comes to the internet with some trying to impose borders in cyberspace to extend their physical borders in cyberspace. From attempts to create isolatable domestic internets to data localization laws and to increased calls for sovereignty in the digital space, all these approaches are raising concerns regarding the fate of the internet.While the impact of these approaches varies and the motivations behind them are arguably different too, all governments have been working towards the pursuit of greater technological independence and in some instances greater control.The panellists will discuss the impact that these approaches have on the internet. They will address the question of whether the era of an 'open web' is drawing to an end and whether these territorialization efforts lead to a fragmentation of the internet, making a 'splinternet' inevitable?This event is being organized with the kind support of DXC Technology.This event will be followed by a reception. PLEASE NOTE THIS EVENT IS POSTPONED UNTIL FURTHER NOTICE. Department/project International Security Programme, Internet Governance Esther Naylor Research Assistant, International Security Programme +44 (0)20 7314 3628 Email Full Article
of Local Pathways Towards De-escalation of Libya's Conflict By feedproxy.google.com Published On :: Wed, 22 Jan 2020 10:20:01 +0000 Invitation Only Research Event 28 January 2020 - 3:00pm to 4:30pm Chatham House | 10 St James's Square | London | SW1Y 4LE Event participants Usama Otman Essed, Libya Center for Strategic & Future StudiesChair: Tim Eaton, Middle East and North Africa Programme, Chatham House A shaky truce remains broadly in place among rival Libyan forces fighting for control of Tripoli. However, a durable ceasefire to bring an end to the current bout of conflict, which was initiated by Khalifa Haftar’s Libyan Arab Armed Forces’ (LAAF) offensive on the capital in April 2019, has not been reached. In recent weeks attention has focused on talks hosted in Moscow and Berlin, with the former aimed at agreeing a ceasefire and the latter seeking to reach agreement among international actors to bring an end to external military support for Libyan warring actors, and to craft a way forward for future intra-Libyan talks. Yet, there has been little emphasis on Libyan actors – beyond Haftar and prime minister Fayez al-Serraj – in this process. This roundtable will bring together experts and policymakers to discuss means of de-escalating the conflict and seeking a lasting resolution through the development of interconnected intra-Libyan social and security negotiation tracks. Mr Usama Otman Essed of the Libya Center for Strategic and Future Studies (LCSFS) will present his research group’s ideas on these issues and discuss their ongoing efforts to promote dialogue among social and security actors.Attendance at this event is by invitation only. Event attributes Chatham House Rule Department/project Middle East and North Africa Programme Reni Zhelyazkova Programme Coordinator, Middle East and North Africa Programme +44 (0)20 7314 3624 Email Full Article
Reni Zhelyazkova Programme Coordinator, Middle East and North Africa Programme +44 (0)20 7314 3624 Email
of Lebanon Is Paying the Cost of Its Dysfunctional Politics By feedproxy.google.com Published On :: Wed, 26 Feb 2020 05:27:10 +0000 26 February 2020 Nadim Shehadi Associate Fellow, Middle East and North Africa Programme @Confusezeus A series of fights to political stalemate have led its economy to the brink and cut it off from its natural economic partners in the Gulf. 2020-02-25-Leb1.jpg Protests against economic conditions and government inaction turned violent in January. Photo: Getty Images. To understand Lebanon’s financial collapse, look to its politics.The country has been deeply damaged by an increasingly dysfunctional political system. A series of compromises have alienated it from its main markets in the Gulf and strangled its economy; anyone that has glanced at fluctuations in Lebanese bank deposits over the last 10 years can see the correlation.Imagine if Boris Johnson or Donald Trump were obliged to form joint governments with Jeremy Corbyn or Bernie Sanders. The result would be paralysis and lack of accountability as each party pulls the country in opposite directions and blames the other for the state of limbo. This has been the state of affairs in Lebanon since the Doha agreement of 2008. That agreement followed an 18-month siege that paralyzed Beirut and an attack on the city by Hezbollah’s ‘black shirts’. The Doha formula imposed governments of national unity between Prime Minister Saad Hariri’s pro-Saudi camp and Hezbollah’s pro-Iran camp and their respective internal allies.The pattern was set: each period of subsequent paralysis was followed by further compromise as the tug of war pulled the country away from its principal economic partners, the Arab Gulf states, with the regional balance of power tilting towards Hezbollah. It was not supposed to be like this. The Baabda Declaration in June 2012, reached after a process of national dialogue, was meant to secure Lebanon’s neutrality in regional conflicts, with both sides promising to hold back on external alliances and coexist despite difference over major regional issues like the war in Syria, the standoff between the US and Iran or relations with Israel or the Gulf states.This has worn away. The Baabda declaration itself became a sham when Hezbollah inserted itself into the war in Syria in support of the Assad regime and overtly got involved in Iraq and Yemen as an Iranian proxy. This was followed by Saudi opposition to concessions by Hariri that led to the election of General Michel Aoun, an ally of Hezbollah, as president in October 2016; again, after a political paralysis that lasted 29 months with no active government and no head of state. The Saudis were also furious when President Aoun’s son-in-law, Foreign Minister Gebran Bassil, abstained from condemning the burning of the Saudi embassy in Tehran at an Arab League meeting in Cairo in January 2016, citing the need to preserve national unity.Fearing that he was simply providing Hezbollah with protection in the guise of compromise, the Saudis pressured Hariri to resign in November 2017 during a trip to Riyadh, but he later challenged that by retracting on his resignation when back in Beirut. Lebanon was caught between two sides, and as the regional conflict intensified from tension to open confrontation, neutrality was no longer an option.Gulf connectionsAn estimated 350,000 Lebanese expats live and work in Saudi Arabia, the UAE, Qatar and Kuwait. These countries are also the main clients for Lebanese contractors, consultants and advertising companies, some of which have offices there. The domestic tourism industry relies heavily on Arab Gulf visitors and they are a principal source of foreign investments especially in the real estate sector.Lebanon also enjoyed a certain degree of political and economic protection from the US and the Gulf, and Hezbollah benefited indirectly from that protection, as it also shielded it to a certain degree from sanctions.The deterioration of relations meant that the country was cut off by its Gulf partners. This was manifested in travel bans for Gulf Cooperation Council (GCC) nationals to Lebanon and a decrease in investments and bank deposits, as well as a decrease in remittances from Lebanese expats, partly because of economic crisis in the Gulf countries themselves.Saudi Arabia withdrew $4 billion of aid to the Lebanese army and internal security forces, and no aid or deposits were forthcoming as the economic and financial situation deteriorated. The costs to the Lebanese economy include the opportunity cost created by the annual threat of war with Israel, after which trips are cancelled and projects postponed. Hezbollah also controls a section of Beirut port where it pays no duty or taxes. Add to that the economic fallout from the war in Syria, such as the impact on exports, the inflow of refugees and the cost of Hezbollah’s involvement.The burden of these political factors is difficult to estimate but it constitutes the ransom that the Lebanese economy bears as a cost of the compromise. This is not to absolve Lebanese politicians from corruption or bankers of mismanagement but to add that political factors cannot be ignored.The cumulative cost and economic impact of being cut off from its main economic partner eventually bankrupted the country. The fiscal and financial aspects, with Lebanon’s inability to service its debt, are but a reflection of these political factors. In the long run, the key to avoiding complete collapse is to restore relations with the GCC and free Lebanon from that very costly grip. Full Article
of Unpacking the role of religion in political transnationalism: the case of the Shi'a Iraqi diaspora since 2003 By feedproxy.google.com Published On :: Wed, 04 Mar 2020 12:58:04 +0000 4 March 2020 , Volume 96, Number 2 Oula Kadhum Read Online This article explores the role of religion in political transnationalism using the case of the Shi'a Iraqi diaspora since 2003. The article focuses on three areas that capture important trends in Shi'a transnationalism and their implications for transnational Shi'a identity politics. These include Shi'a diasporic politics, transnational Shi'a civic activism, and the cultural production of Iraqi Shi'a identity through pilgrimages, rituals and new practices. It is argued that understanding Shi'a Islam and identity formation requires adopting a transnational lens. The evolution of Shi'a Islam is not only a result of the dictates of the Shi'a clerical centres, and how they influence Shi'a populations abroad, but also the transnational interrelationships and links to holy shrine cities, Shi'i national and international politics, humanitarianism and commemorations and rituals. The article demonstrates that Shi'a political transnationalism is unexceptional in that it echoes much of the literature on diasporic politics and development where diaspora involve themselves from afar in the politics and societies of their countries of origin. At the same time, it shows the exceptionalism of Shi'a diasporic movements, in that their motivations and mobilizations are contributing to the reification of sectarian geographical and social borders, creating a transnationalism that is defined by largely Shi'a networks, spaces, actors and causes. The case of Shi'a political transnationalism towards Iraq shows that this is increasing the distance between Shi'is and Iraq's other communities, simultaneously fragmenting Iraq's national unity while deepening Shi'a identity and politics both nationally and supra-nationally. Full Article
of POSTPONED: The Development of Libyan Armed Groups since 2014: Community Dynamics and Economic Interests By feedproxy.google.com Published On :: Wed, 04 Mar 2020 14:15:01 +0000 Invitation Only Research Event 18 March 2020 - 9:00am to 10:30am Chatham House | 10 St James's Square | London | SW1Y 4LE Event participants Abdul Rahman Alageli, Associate Fellow, MENA Programme, Chatham HouseEmaddedin Badi, Non-Resident Scholar, Middle East InstituteTim Eaton, Senior Research Fellow, MENA Programme Chatham HouseValerie Stocker, Independent Researcher Since the overthrow of the regime of Muammar Gaddafi in 2011, Libya’s multitude of armed groups have followed a range of paths. While many of these have gradually demobilized, others have remained active, and others have expanded their influence. In the west and south of the country, armed groups have used their state affiliation to co-opt the state and professionals from the state security apparatus into their ranks.In the east, the Libyan Arab Armed Forces projects a nationalist narrative yet is ultimately subservient to its leader, Field Marshal Khalifa Haftar. Prevailing policy narratives presuppose that the interests of armed actors are distinct from those of the communities they claim to represent. Given the degree to which most armed groups are embedded in local society, however, successful engagement will need to address the fears, grievances and desires of the surrounding communities, even while the development of armed groups’ capacities dilutes their accountability to those communities.This roundtable will discuss the findings of a forthcoming Chatham House research paper, ‘The Development of Libyan Armed Groups Since 2014: Community Dynamics and Economic Interests’, which presents insights from over 200 interviews of armed actors and members of local communities and posits how international policymakers might seek to curtail the continued expansion of the conflict economy.PLEASE NOTE THIS EVENT IS POSTPONED UNTIL FURTHER NOTICE. Event attributes Chatham House Rule Department/project Middle East and North Africa Programme, Countering Conflict Economies in MENA, Libya’s Conflict Economy Georgia Cooke Project Manager, Middle East and North Africa Programme +44 (0)20 7957 5740 Email Full Article
of The Development of Libyan Armed Groups Since 2014: Community Dynamics and Economic Interests By feedproxy.google.com Published On :: Mon, 16 Mar 2020 17:25:16 +0000 17 March 2020 This paper explores armed group–community relations in Libya and the sources of revenue that have allowed armed groups to grow in power and influence. It draws out the implications for policy and identifies options for mitigating conflict dynamics. Read online Download PDF Tim Eaton Senior Research Fellow, Middle East and North Africa Programme @el_khawaga LinkedIn Abdul Rahman Alageli Associate Fellow, Middle East and North Africa Programme @abdulrahmanlyf Emadeddin Badi Policy Leader Fellow, School of Transnational Governance, European University Institute Mohamed Eljarh Co-founder and CEO, Libya Outlook Valerie Stocker Researcher Amru_24-2_13.jpg Fighters of the UN-backed Government of National Accord patrol in Ain Zara suburb in Tripoli, February 2020. Photo: Amru Salahuddien SummaryLibya’s multitude of armed groups have followed a range of paths since the emergence of a national governance split in 2014. Many have gradually demobilized, others have remained active, and others have expanded their influence. However, the evolution of the Libyan security sector in this period remains relatively understudied. Prior to 2011, Libya’s internal sovereignty – including the monopoly on force and sole agency in international relations – had been personally vested in the figure of Muammar Gaddafi. After his death, these elements of sovereignty reverted to local communities, which created armed organizations to fill that central gap. National military and intelligence institutions that were intended to protect the Libyan state have remained weak, with their coherence undermined further by the post-2014 governance crisis and ongoing conflict. As a result, the most effective armed groups have remained localized in nature; the exception is the Libyan Arab Armed Forces (LAAF), which has combined and amalgamated locally legitimate forces under a central command.In the west and south of the country, the result of these trends resembles a kind of inversion of security sector reform (SSR) and disarmament, demobilization and reintegration (DDR): the armed groups have used their state affiliation to co-opt the state and professionals from the state security apparatus into their ranks; and have continued to arm, mobilize and integrate themselves into the state’s security apparatus without becoming subservient to it. In the eastern region, the LAAF projects a nationalist narrative yet is ultimately subservient to its leader, Field Marshal Khalifa Haftar. The LAAF has co-opted social organizations to dominate political and economic decision-making.The LAAF has established a monopoly over the control of heavy weapons and the flow of arms in eastern Libya, and has built alliances with armed groups in the east. Armed groups in the south have been persuaded to join the LAAF’s newly established command structure. The LAAF’s offensive on the capital, which started in April 2019, represents a serious challenge to armed groups aligned with the Tripoli-based Government of National Accord (GNA). The fallout from the war will be a challenge to the GNA or any future government, as groups taking part in the war will expect to be rewarded. SSR is thus crucial in the short term: if the GNA offers financial and technical expertise and resources, plus legal cover, to armed groups under its leadership, it will increase the incentive for armed groups to be receptive to its plans for reform.Prevailing policy narratives presuppose that the interests of armed actors are distinct from those of the communities they claim to represent. Given the degree to which most armed groups are embedded in local society, however, successful engagement will necessarily rely on addressing the fears, grievances and desires of the surrounding communities. Yet the development of armed groups’ capacities, along with their increasing access to autonomous means of generating revenue, has steadily diluted their accountability to local communities. This process is likely to be accelerated by the ongoing violence around Tripoli.Communities’ relationship to armed groups varies across different areas of the country, reflecting the social, political, economic and security environment:Despite their clear preference for a more formal, state-controlled security sector, Tripoli’s residents broadly accept the need for the presence of armed groups to provide security. The known engagement of the capital’s four main armed groups in criminal activity is a trade-off that many residents seem able to tolerate, providing that overt violence remains low. Nonetheless, there is a widespread view that the greed of Tripoli’s armed groups has played a role in stoking the current conflict.In the east, many residents appear to accept (or even welcome) the LAAF’s expansion beyond the security realm, provided that it undertakes these roles effectively. That said, such is the extent of LAAF control that opposition to the alliance comes at a high price.In the south, armed groups draw heavily on social legitimacy, acting as guardians of tribal zones of influence and defenders of their respective communities against outside threats, while also at times stoking local conflicts. Social protections continue to hold sway, meaning that accountability within communities is also limited.To varying extents since 2014, Libya’s armed groups have developed networks that enmesh political and business stakeholders in revenue-generation models:Armed groups in Tripoli have compensated for reduced financial receipts from state budgets by cultivating unofficial and illicit sources of income. They have also focused on infiltrating state institutions to ensure access to state budgets and contracts dispersed in the capital.In the east of the country, the LAAF has developed a long-term strategy to dominate the security, political and economic spheres through the establishment of a quasi-legal basis for receiving funds from Libya’s rival state authorities. It has supplemented this with extensive intervention in the private sector. External patronage supports military operations, but also helps to keep this financial system, based on unsecured debt, afloat.In the south, limited access to funds from the central state has spurred armed groups to become actively involved in the economy. This has translated into the taxation of movement and the imposition of protection fees, particularly on informal (and often illicit) activity.Without real commitment from international policymakers to enforcing the arms embargo and protecting the economy from being weaponized, Libya will be consigned to sustained conflict, further fragmentation and potential economic collapse. Given the likely absence of a political settlement in the short term, international policymakers should seek to curtail the continued expansion of the conflict economy by reducing armed groups’ engagement in economic life.In order to reduce illicit activities, international policymakers should develop their capacity to identify and target chokepoints along illicit supply chains, with a focus on restraining activities and actors in closest proximity to violence. Targeted sanctions against rent maximizers (both armed and unarmed) is likely to be the most effective strategy. More effective investigation and restraint of conflict economy actors will require systemic efforts to improve transparency and enhance the institutional capacity of anti-corruption authorities. International policymakers should also support the development of tailored alternative livelihoods that render conflict economy activities less attractive. Department/project Middle East and North Africa Programme, Chaos States, Countering Conflict Economies in MENA, Libya’s Conflict Economy Full Article
of COVID-19 and the Iranian Shadows of War By feedproxy.google.com Published On :: Wed, 08 Apr 2020 13:24:47 +0000 8 April 2020 Dr Sanam Vakil Deputy Director and Senior Research Fellow, Middle East and North Africa Programme @SanamVakil Coronavirus has plunged Iran into the country’s biggest crisis since its war with Iraq. More than 30 years later, the lingering effects of the war are shaping Iran’s reaction to the pandemic. 2020-04-08-Iran-COVID-Tehran Spraying disinfectant at Tajrish bazaar in Tehran, Iran, during the coronavirus pandemic in March 2020. Photo by Majid Saeedi/Getty Images. In the face of the COVID-19 pandemic, many global leaders have invoked war analogies – from the Pearl Harbor attack to the collective spirit on display during the Second World War – to highlight past lessons learned or rally their populations.For Iran’s leadership, more recent war analogies hold resonance and help explain the ideological and political conundrum limiting an effective COVID-19 response. While the Islamic Republic has weathered a multitude of challenges, COVID-19 is putting unprecedented strain on Iran’s already fragile, heavily-sanctioned economy and further exposing domestic political fissures amid ongoing international tensions.Iran has been identified as the regional epicentre of the pandemic with a steadily rising number of deaths, including several of the country’s political and military elite. Yet the Iranian government has not evoked the collective memory of the war as an opportunity for national resistance and mobilization.Sluggish and poorly managedThis is unsurprising, because thus far the Iranian government’s response to COVID-19 has been sluggish and poorly managed. After an initial slow response, Iran then attempted to downplay the impact of the virus, covering up the number of cases and deaths and blaming the United States, before implementing a poorly coordinated action plan marred by government infighting.For the Iranian leadership, the Iran-Iraq war has been the single most influential and defining period – it has impacted its political ideology, domestic and security policies and international relations. More than half a million Iranians died, and a paranoid worldview and sense of isolation was cemented among many elite leaders such as Supreme Leader Ali Khamenei.The war created a valiant culture of leadership from Qassem Soleimani to presidents Mahmoud Ahmadinejad and Hashemi Rafsanjani and, over time, has resulted in the development of Iran’s asymmetrical defense capabilities.The war enabled a dark purge of political opponents and the gradual birth of Iran’s reformist faction, all while the ethos of sacrifice and martyrdom was linked to the collective notions of resistance.These would be carried forward in other resistance campaigns both regional and economic. Most defining was Ayatollah Khomeini’s infamous 1988 decision to ‘drink the poisoned chalice’ and end the long war. Three decades later, Iran continues to contend with those outcomes.To acknowledge that the COVID-19 crisis could have equally profound consequences would add further pressure to the Islamic Republic at a time of incomparable vulnerability. Even before this crisis, the Iranian government linked sanctions to economic warfare, making future negotiations conditional on sanctions relief.Iranian hardliners used the opportunity to promote Iran’s subsistence-based resistance economy designed to insulate Iran’s economy from external shocks such as sanctions. While both groups recognize the economic urgency, their contending strategies help explain the muddled government response and the ongoing ideological competition between the political elites.Rouhani has argued that a full lockdown of the Iranian economy is impossible because it is already under significant strain from sanctions - the Iranian economy experienced a 9.5% contraction in 2019 and is expected to worsen in the coming year.That said, through Iran’s New Year holidays the government did take action to slow the spread of the virus, discouraging travel and shutting schools, pilgrimage sites and cancelling Friday prayers. Finally, on 4 April, after receiving permission from Khamenei to do so, Rouhani withdrew $1 billion from Iran’s National Development Fund and is distributing the money through loans and credits to 23 million households.Aid from a number of Iran’s parastatal agencies was also announced. Conversely, in his annual New Year’s speech the supreme leader securitized the crisis by laying blame on the United States for spreading the virus as a form of biological terrorism. Iran’s army chief of staff Major General Bagheri was tasked with building hospitals and the Islamic Revolution Guard Corps given authority to clear the streets.The recent expulsion of Médecins Sans Frontières from Iran highlights the mix of paranoia and resistance culture still on display. US sanctions on Iran have significantly weakened Iran’s economy and limited Tehran’s ability to purchase much needed medical supplies and equipment. Unable to access its foreign reserves due to sanctions, the Rouhani government has applied for a $5 billion loan from the IMF.European countries alongside a number of US members of congress have appealed to the Trump administration to ease sanctions on humanitarian grounds. While Washington continues to pursue its steadfast approach, referring to Iran’s campaign as a ‘sanctions relief scam’, Germany, France, and the UK have offered $5 million in aid and launched INSTEX – a trading mechanism designed to circumvent sanctions to allow non-sanctioned humanitarian trade.The impact of coronavirus on Iranian society remains to be seen. But the impact of sanctions has placed heavy economic and psychological burden on the people. Feeling abandoned by the Iranian state and the United States could produce a mix of contradictory nationalistic and independent impulses.The social contract – already fragile amid protests and government repression – reveals declining trust. Without national mobilization and calls for unity reminiscent of the war period, Iranians have stepped in, highlighting the continued resilience of civil society. Support for the medical establishment has been celebrated throughout the country and on social media. Charities, the private sector - through one initiative known as Campaign Nafas (Breathe) - and diaspora groups have initiated fundraising drives and assistance measures.Iran’s relations with the international community, and specifically the United States, remain an unresolved consequence of the war. The 2015 Iranian nuclear agreement was the closest Tehran and Washington came to resolving decades of tensions, containment and sanctions.COVID-19 has further heightened the trajectory of tensions between Tehran and Washington suggesting that any new deal, while necessary, is not on the cards. Tit-for-tat military exchanges have been on the rise in Iraq and Yemen while American and Iranian leaders issue threats and warnings of potential escalation.Abdullah Nasseri, an advisor to Iran’s reformists, recently stated that in order to manage the coronavirus crisis, the Iranian government needed to make a decision akin to the 1988 United Nations resolution 598 that ended war hostilities. Ayatollah Khomeini famously commented on that ceasefire, stating: ‘Happy are those who have departed through martyrdom. Unhappy am I that I still survive.… Taking this decision is more deadly than drinking from a poisoned chalice. I submitted myself to Allah's will and took this drink for His satisfaction’. While a similar compromise today might appear deadly to the political establishment, it is clear that a paradigm shift away from the shadows of Iran’s last war is urgently needed to manage the challenges stemming from COVID-19. Full Article
of Webinar: Are the Gulf Standoffs Resolvable? By feedproxy.google.com Published On :: Wed, 15 Apr 2020 08:15:01 +0000 Research Event 21 April 2020 - 1:00pm to 2:00pm Event participants David Roberts, Assistant Professor and School of Security Studies Lead for Regional Security and Development, King's College LondonKristian Coates Ulrichsen, Associate Fellow, Middle East and North Africa Programme, Chatham HouseChair: Sanam Vakil, Deputy Director and Senior Research Fellow, Middle East and North Africa Programme, Chatham House This webinar, part of the MENA Programme Webinar Series, will examine the trajectory of political and security dynamics in the Gulf in view of the ongoing rift within the Gulf Cooperation Council (GCC), the death of Sultan Qaboos in Oman, the escalation of tensions between Iran and the United States, and the COVID-19 crisis.Speakers will explore the orientation of the GCC under a new Secretary-General and the prospects for mediation between Qatar and its neighbours, the future of Omani domestic and foreign policy under Sultan Haitham bin Tariq Al Said, eventual transitions to new leadership in Bahrain and Kuwait, and whether the impact of COVID-19 may help replace the confrontation within the GCC with closer coordination among its six member states.The webinar will be livestreamed on the MENA Programme Facebook page. Department/project Middle East and North Africa Programme, Future Dynamics in the Gulf Reni Zhelyazkova Programme Coordinator, Middle East and North Africa Programme +44 (0)20 7314 3624 Email Full Article
Reni Zhelyazkova Programme Coordinator, Middle East and North Africa Programme +44 (0)20 7314 3624 Email
of Webinar: Reimagining the Role of State and Non-State Actors in (Re)building National Health Systems in the Arab World By feedproxy.google.com Published On :: Wed, 15 Apr 2020 14:15:01 +0000 Research Event 22 April 2020 - 1:00pm to 2:00pm Event participants Fadi El-Jardali, Professor of Health Policy and Systems, American University of BeirutModerator: Nadim Houry, Executive Director, Arab Reform Initiative As new cases of COVID-19 continue to surge, countries around the world struggle to mitigate the public health and economic effects of the virus. It is becoming increasingly clear that an effective pandemic response requires a whole-of-government, whole-of-society approach. In the Arab world, where health systems are already strained by armed conflicts and displaced populations, a whole-of-society response to the pandemic is particularly critical as countries have become increasingly dependent on non-state actors, notably the private sector, for healthcare provision and any response that includes the state alone may not be sufficient to address the pandemic.In a recent article, Fadi El-Jardali, argued that while the pandemic will have grave health and economic consequences for years to come, it brings with it a valuable opportunity to re-envision the role of state and non-state actors in strengthening health systems. The article addressed the need for increased collaboration between state and non-state actors, and the rethinking of existing cooperation models to provide quality healthcare services for all. In this webinar, part of the Chatham House project on the future of the state in the Middle East and North Africa, Dr El-Jardali will discuss how state and non-state actors can collaborate more effectively to address the shortcomings of national health care systems amidst the pandemic and beyond. The article’s author will share insights on the different capacities available in Arab societies that governments can draw upon to ensure that Universal Health Coverage, equity considerations and social justice are at the core of health systems.You can express your interest in attending by following this link. You will receive a Zoom confirmation email should your registration be successful. Alternatively, you can watch the event live on the MENA Programme Facebook page. Department/project Middle East and North Africa Programme, The Future of the State in the Middle East Reni Zhelyazkova Programme Coordinator, Middle East and North Africa Programme +44 (0)20 7314 3624 Email Full Article
Reni Zhelyazkova Programme Coordinator, Middle East and North Africa Programme +44 (0)20 7314 3624 Email
of Breaking the Cycle of Violence: Transitional Justice for the Victims of ISIS in Syria By feedproxy.google.com Published On :: Mon, 27 Apr 2020 15:50:01 +0000 28 April 2020 This paper aims to assist the region’s local authorities, and their key foreign backers, in understanding how transitional justice can provide alternative avenues for holding local ISIS members to account while contributing to the healing of communities. Read online Download PDF Haid Haid Senior Consulting Fellow, Middle East and North Africa Programme @HaidHaid22 2020-04-28-Syria-prison.jpg A fighter with the Syrian Democratic Forces monitors prisoners accused of being affiliated with ISIS, at a prison in the northeastern Syrian city of Hassakeh on 25 October 2019. Photo: Getty Images. SummaryFollowing the territorial defeat of Islamic State of Iraq and Syria (ISIS) in northeastern Syria, the Kurdish-led autonomous administration in the region is now grappling with the task of quickly dealing with thousands of the group’s detained members while bringing justice to their victims. To that end, local authorities are focusing on the use of counterterrorism laws and courts to charge captured ISIS members and determine their guilt accordingly.The piecemeal approach to justice is deeply flawed, and raises particular concerns about due process. No precise instruments exist to determine the personal responsibility of ISIS individuals for specific crimes, or for their role in war crimes committed by the group. In any event, the scale of the crimes and the number of victims – as well as severe shortages of resources and workers – make dispensation of justice extremely difficult through the traditional legal system.Not all detained ISIS members receive prison sentences. Individuals who did not hold senior roles in the group’s apparatus and are not accused of ‘major’ crimes (in practice, largely defined as fighting for ISIS and murder) are being released under limited reconciliation deals with tribal leaders. But the involvement of local community leaders in those efforts is not enough to ensure positive results. Many victims are upset at seeing ISIS members walk free without even admitting their guilt publicly or apologizing for the pain they caused.To overcome the limitations of the current, counterterrorism-focused framework, a ‘transitional justice’ approach could provide judicial and non-judicial instruments to establish accountability for ISIS crimes and reduce community resistance to the reintegration of group members. A combination of non-judicial mechanisms such as truth commissions, missing persons’ committees, and reparations and victim-healing programmes could play a vital role in providing ISIS victims with a sense of justice while contributing to peacebuilding and stability.Ignoring the urgency of developing a long-term plan to serve justice and contribute to community healing will almost certainly allow ISIS to continue to prevent the recovery and development of northeastern Syria. This, in turn, risks undermining the stability of the country and the region at large. Department/project Middle East and North Africa Programme Full Article
of Lebanese Women and the Politics of Disruption By feedproxy.google.com Published On :: Thu, 30 Apr 2020 11:00:01 +0000 Research Event 6 May 2020 - 1:00pm to 2:00pm Event participants Carmen Geha, Assistant Professor of Public Administration, Leadership and Organisational Development, American University of BeirutModerator: Lina Khatib, Director, Middle East and North Africa Programme, Chatham House Lebanese women have been at the forefront of the protest movement that has shaken Lebanon since October 2019. The active participation by women and their visibility in Lebanon's protest movement has challenged the gender norms prevalent in Lebanese society and politics. However, the COVID-19 pandemic and the nationwide lockdown that ensued has disrupted women's ability to organize, and is threatening the fragile progress towards female inclusion in the political process. In a recent article, Carmen Geha discussed the politics of representation in the context of women's participation in public life in Lebanon and argued that the country's political system is maintained through tightly-knit informal power relations among sectarian politicians, making women's participation in politics virtually impossible. The article explained how the October 2019 revolution challenged that norm by creating inclusive spaces where women activists could confront politicians and thus, transform the way women participate in politics and public life. In this webinar, part of the Chatham House project on the future of the state in the Middle East and North Africa, the article's author will discuss how women's activism in Lebanon has been affected by the coronavirus-induced lockdown. The speaker will consider how, under current circumstances, women activists can speak up collectively and bring back a movement to contest gender norms in order to build an alternative political model that can better represent women's priorities. You can express your interest in attending by following this link. You will receive a Zoom confirmation email should your registration be successful. Alternatively, you can watch the event live on the MENA Programme Facebook page. Department/project Middle East and North Africa Programme, The Future of the State in the Middle East Reni Zhelyazkova Programme Coordinator, Middle East and North Africa Programme +44 (0)20 7314 3624 Email Full Article
Reni Zhelyazkova Programme Coordinator, Middle East and North Africa Programme +44 (0)20 7314 3624 Email
of Webinar: Breaking the Cycle of Violence: Transitional Justice for the Victims of ISIS in Syria By feedproxy.google.com Published On :: Wed, 06 May 2020 09:05:01 +0000 Research Event 12 May 2020 - 2:00pm to 3:00pmAdd to CalendariCalendar Outlook Google Yahoo Haid Haid, Senior Consulting Fellow, Middle East and North Africa Programme, Chatham HouseSara Kayyali, Syria Researcher, Middle East and North Africa Division, Human Rights WatchModerator: Lina Khatib, Director, Middle East and North Africa Programme, Chatham House You can register your interest here. Alternatively, you can watch the webinar live on the MENA Programme Facebook page.Following the territorial defeat of Islamic State of Iraq and Syria (ISIS) in northeastern Syria, the Kurdish-led autonomous administration in the region is now grappling with the task of quickly dealing with thousands of the group’s detained members while bringing justice to their victims. To that end, local authorities are focusing on the use of counterterrorism laws and courts to charge captured ISIS members and determine their guilt accordingly.In a recent research paper, author Haid Haid argues that this approach to justice is deeply flawed as it raises concerns about due process and lacks the precise instruments to determine the personal responsibility of ISIS individuals for specific crimes, or for their role in war crimes committed by the group. The paper proposes that a ‘transitional justice’ approach could provide judicial and non-judicial instruments to establish accountability for ISIS crimes and reduce community resistance to the reintegration of group members.In this webinar, part of the MENA Programme’s Online Event Series, speakers will examine the benefits of such an approach to justice for overcoming the limitations of the current, counterterrorism-focused framework. Panelists will discuss the alternative mechanisms local authorities and their key foreign backers can use to hold local ISIS members to account while contributing to the healing of communities. The event will be held on the record. Reni Zhelyazkova Programme Coordinator, Middle East and North Africa Programme +44 (0)20 7314 3624 Email Department/project Middle East and North Africa Programme, Syria from Within Full Article
Reni Zhelyazkova Programme Coordinator, Middle East and North Africa Programme +44 (0)20 7314 3624 Email
of Politics, policy-making and the presence of images of suffering children By feedproxy.google.com Published On :: Thu, 07 May 2020 08:45:52 +0000 7 May 2020 , Volume 96, Number 3 Helen Berents Read Online In 2017 Trump expressed pity for the ‘beautiful babies’ killed in a gas attack on Khan Shaykhun in Syria before launching airstrikes against President Assad's regime. Images of suffering children in world politics are often used as a synecdoche for a broader conflict or disaster. Injured, suffering, or dead; the ways in which images of children circulate in global public discourse must be critically examined to uncover the assumptions that operate in these environments. This article explores reactions to images of children by representatives and leaders of states to trace the interconnected affective and political dimensions of these images. In contrast to attending to the expected empathetic responses prompted by images of children, this article particularly focuses on when such images prompt bellicose foreign policy decision-making. In doing this, the article forwards a way of thinking about images as contentious affective objects in international relations. The ways in which images of children's bodies and suffering are strategically deployed by politicians deserves closer scrutiny to uncover the visual politics of childhood inherent in these moments of international politics and policy-making. Full Article
of Soundscapes of war: the audio-visual performance of war by Shi'a militias in Iraq and Syria By feedproxy.google.com Published On :: Thu, 07 May 2020 09:16:54 +0000 7 May 2020 , Volume 96, Number 3 Helle Malmvig Read online This article sets out to bring sound and music to the field of visual studies in International Relations. It argues that IR largely has approached the visual field as if it was without sound; neglecting how audial landscapes frame and direct our interpretation of moving imagery. Sound and music contribute to making imagery intelligible to us, we ‘hear the pictures’ often without noticing. The audial can for instance articulate a visual absence, or blast visual signs, bring out certain emotional stages or subjects’ inner life. Audial frames steer us in distinct directions, they can mute the cries of the wounded in war, or amplify the sounds of joy of soldiers shooting in the air. To bring the audial and the visual analytically and empirically together, the article therefore proposes four key analytical themes: 1) the audial–visual frame, 2) point of view/point of audition, 3) modes of audio-visual synchronization and 4) aesthetics moods. These are applied to a study of ‘war music videos’ in Iraq and Syria made and circulated by Shi'a militias currently fighting there. Such war music videos, it is suggested, are not just artefacts of popular culture, but have become integral parts of how warfare is practiced today, and one that is shared by soldiers in the US and Europe. War music videos are performing war, just as they shape how war is known by spectators and participants alike. Full Article
of Evidence Against an Important Role of Plasma Insulin and Glucagon Concentrations in the Increase in EGP Caused by SGLT2 Inhibitors By diabetes.diabetesjournals.org Published On :: 2020-03-20T11:50:28-07:00 Sodium–glucose cotransport 2 inhibitors (SGLT2i) lower plasma glucose but stimulate endogenous glucose production (EGP). The current study examined the effect of dapagliflozin on EGP while clamping plasma glucose, insulin, and glucagon concentrations at their fasting level. Thirty-eight patients with type 2 diabetes received an 8-h measurement of EGP ([3-3H]-glucose) on three occasions. After a 3-h tracer equilibration, subjects received 1) dapagliflozin 10 mg (n = 26) or placebo (n = 12); 2) repeat EGP measurement with the plasma glucose concentration clamped at the fasting level; and 3) repeat EGP measurement with inhibition of insulin and glucagon secretion with somatostatin infusion and replacement of basal plasma insulin and glucagon concentrations. In study 1, the change in EGP (baseline to last hour of EGP measurement) in subjects receiving dapagliflozin was 22% greater (+0.66 ± 0.11 mg/kg/min, P < 0.05) than in subjects receiving placebo, and it was associated with a significant increase in plasma glucagon and a decrease in the plasma insulin concentration compared with placebo. Under glucose clamp conditions (study 2), the change in plasma insulin and glucagon concentrations was comparable in subjects receiving dapagliflozin and placebo, yet the difference in EGP between dapagliflozin and placebo persisted (+0.71 ± 0.13 mg/kg/min, P < 0.01). Under pancreatic clamp conditions (study 3), dapagliflozin produced an initial large decrease in EGP (8% below placebo), followed by a progressive increase in EGP that was 10.6% greater than placebo during the last hour. Collectively, these results indicate that 1) the changes in plasma insulin and glucagon concentration after SGLT2i administration are secondary to the decrease in plasma glucose concentration, and 2) the dapagliflozin-induced increase in EGP cannot be explained by the increase in plasma glucagon or decrease in plasma insulin or glucose concentrations. Full Article
of PARP-1-targeted Auger emitters display high-LET cytotoxic properties in vitro but show limited therapeutic utility in solid tumor models of human neuroblastoma By jnm.snmjournals.org Published On :: 2019-11-01T13:36:37-07:00 The currently available therapeutic radiopharmaceutical for high-risk neuroblastoma, 131I-MIBG, is ineffective at targeting micrometastases due to the low linear energy transfer (LET) properties of high-energy beta particles. In contrast, Auger radiation has high-LET properties with nanometer ranges in tissue, efficiently causing DNA damage when emitted in close proximity to DNA. The aim of this study was to evaluate the cytotoxicity of targeted Auger therapy in pre-clinical models of high-risk neuroblastoma. Methods: Using a radiolabeled poly(ADP-ribose) polymerase (PARP) inhibitor, 125I-KX1, we delivered an Auger emitter iodine-125 to PARP-1: a chromatin-binding enzyme overexpressed in neuroblastoma. In vitro cytotoxicity of 125I-KX1 was assessed in nineteen neuroblastoma cell lines, followed by in-depth pharmacological analysis in a sensitive and resistant pair of cell lines. Immunofluorescence microscopy was used to characterize 125I-KX1-induced DNA damage. Finally, in vitro/in vivo microdosimetry was modeled from experimentally derived pharmacological variables. Results: 125I-KX1 was highly cytotoxic in vitro across a panel of neuroblastoma cell lines, directly causing double strand DNA breaks. Based on subcellular dosimetry, 125I-KX1 was approximately twice as effective compared to 131I-KX1, whereas cytoplasmic 125I-MIBG demonstrated low biological effectiveness. Despite the ability to deliver focused radiation dose to the cell nuclei, 125I-KX1 remained less effective than its alpha-emitting analog 211At-MM4, and required significantly higher activity for equivalent in vivo efficacy based on tumor microdosimetry. Conclusion: Chromatin-targeted Auger therapy is lethal to high-risk neuroblastoma cells with potential use in micrometastatic disease. This study provides the first evidence for cellular lethality from a PARP-1 targeted Auger emitter, calling for further investigation into targeted Auger therapy. Full Article
of 3-year freedom from progression following 68GaPSMA PET CT triaged management in men with biochemical recurrence post radical prostatectomy. Results of a prospective multi-center trial. By jnm.snmjournals.org Published On :: 2019-11-01T13:36:36-07:00 Background: 68Ga PSMA PET CT (PSMA) is increasingly used in men with biochemical recurrence (BCR) post radical prostatectomy (RP), but its longer term prognostic / predictive potential in these men is unknown. The aim of this study was to evaluate the predictive value of PSMA PET for 3 year freedom from progression (FFP) in men with BCR post RP undergoing salvage radiotherapy (sRT). Methods: This prospective multi-center study enrolled 260 men between 2015 and 2017. Eligible patients were referred for PSMA with rising PSA following RP. Management following PSMA was recorded but not mandated. PSMA protocols were standardised across sites and reported prospectively. Clinical, pathological and surgical information, sRT, timing and duration of androgen deprivation (ADT), 3 year PSA results and clinical events were documented. FFP was defined as a PSA rise ≤ 0.2ng/mL above nadir post sRT, with no additional treatment. Results: The median PSA was 0.26ng/mL (IQR 0.15 - 0.59) and follow-up 38 months (IQR 31-43). PSMA was negative in 34.6% (90/260), confined to prostate fossa 21.5% (56/260), pelvic nodes 26.2% (68/260), and distant disease 17.7% (46/260). 71.5% (186/260) received sRT, 38.2% (71/186) to the fossa only, 49.4% (92/186) fossa + pelvic nodes and 12.4% (23/186) nodes alone/SBRT. PSMA was highly predictive of FFP at 3 years following sRT. Overall, FFP was achieved in 64.5% (120/186) of those who received sRT, 81% (81/100) with negative/fossa confined vs. 45% (39/86) for extra fossa disease (p<0.0001). On logistic regression PSMA was more independently predictive of FFP than established clinical predictors, including PSA, T-stage, surgical margin status or Gleason score (P < 0.002). 32% of men with a negative PSMA PET did not receive treatment. Of these, 66% (19/29) progressed, with a mean rise in PSA of 1.59ng/mL over the 3 years. Conclusion: PSMA PET result is highly predictive of FFP at 3 years in men undergoing sRT for BCR following RP. In particular, men with negative PSMA PET or disease identified as still confined to the prostate fossa demonstrate high FFP, despite receiving less extensive radiotherapy and lower rates of additional ADT than those with extra fossa disease. Full Article
of Head-to-head comparison of 68Ga-DOTA-JR11 and 68Ga-DOTATATE PET/CT in patients with metastatic, well-differentiated neuroendocrine tumors: a prospective study By jnm.snmjournals.org Published On :: 2019-11-01T13:36:37-07:00 Purpose: 68Ga-DOTA-JR11 is an antagonist for somatostatin receptor used in neuroendocrine imaging. The purpose of this study is to compare 68Ga-DOTA-JR11 and 68Ga-DOTATATE PET/CT in patients with metastatic, well-differentiated neuroendocrine tumors. Methods: Patients with histologically-proven, metastatic and/or unresectable, well-differentiated neuroendocrine tumors were prospectively recruited in this study. They received an intravenous injection of 68Ga-DOTATATE (4.0 ± 1.3 mCi) on the first day and 68Ga-DOTA-JR11 (4.0 ± 1.4 mCi) on the second day. Whole-body PET/CT scans were performed at 40 to 60 minutes after injection on the same scanner. Physiologic uptake of normal organs, lesion numbers, and lesion uptake were compared. Results: Twenty-nine patients were prospectively enrolled in the study. The SUVmax of the spleen, renal cortex, adrenal glands, pituitary glands, stomach wall, normal liver parenchyma, small intestine, pancreas, and bone marrow were significantly lower on 68Ga-DOTA-JR11 than on 68Ga-DOTATATE PET/CT (P<0.001). 68Ga-DOTA-JR11 detected significantly more liver lesions (539 vs. 356, P = 0.002), but fewer bone lesions (156 vs. 374, P = 0.031, Figure 3) than 68Ga-DOTATATE. The tumor-to-background ratio of liver lesions was significantly higher on 68Ga-DOTA-JR11 (7.6 ± 5.1 vs. 3.4 ± 2.0, P<0.001). 68Ga-DOTA-JR11 and 68Ga-DOTATATE PET/CT showed comparable results for primary tumors and lymph node metastases based on either patient-based or lesion-based comparison. Conclusion: 68Ga-DOTA-JR11 performs better in the detection ability and TBR of liver metastases. However, 68Ga-DOTATATE outperforms 68Ga-DOTA-JR11 in the detection of bone metastases. The differential affinity of different metastatic sites provides key information for patient selection in imaging and peptide receptor radionuclide therapy. Full Article
of Can fluorescence-guided surgery help identify all lesions in unknown locations or is the integrated use of a roadmap created by preoperative imaging mandatory? A blinded study in prostate cancer patients. By jnm.snmjournals.org Published On :: 2019-11-11T12:55:20-08:00 Rationale: Lymphatic tracers can help visualize the lymphatic drainage patterns and sentinel nodes of individual prostate cancer patients. To determine the role of nuclear medicine, in particular the positional guidance of a SPECT/CT-based 3D imaging roadmap, in this process we studied to which extend fluorescence-guidance underestimated the number of target lesions. Methods: SPECT/CT imaging was performed after intraprostatic tracer administration of either ICG-99mTc-nanocolloid (hybrid tracer group) or 99mTc-nanocolloid to create a roadmap that depicted all sentinel nodes (SNs). Patients who received 99mTc-nanocolloid were injected with "free" ICG immediately prior to surgery ("free" ICG group). Before unblinding, fluorescence-guidance was used for intraoperative SN identification. This was followed by extended pelvic lymph node dissection (ePLND). Following unblinding of the SPECT/CT images, the number of missed SN’s were recorded and their resection was pursued when the anatomy allowed. Results: Preoperative SPECT/CT revealed no differences in the SN identification rate between ICG-99mTc-nanocolloid and 99mTc-nanocolloid. However, fluorescence-guidance only allowed intraoperative removal of all SNs in 40% of patients in the hybrid tracer group and in 20% of patients in the "free" ICG group. Overall, 75.9% of the intraoperatively resected SNs in the hybrid tracer group and 51.8% of the SNs in the "free" ICG group were removed solely under fluorescence-guidance. During ePLND 22 additional SNs were resected (7 in the hybrid tracer group and 15 in the "free" ICG group). After unblinding 18 remaining SNs were identified (6 in the hybrid group and 12 in the "free" ICG group). In the "free" ICG group, ex vivo evaluation of the excised specimens revealed that 14 SNs removed under ePLND or after unblinding contained radioactivity but no fluorescence. Conclusion: The preoperative imaging roadmap provided by SPECT/CT enhanced the detection of prostate SNs in more ectopic locations in 17 of the 25 patients and the hybrid tracer ICG-99mTc-nanocolloid was shown to outperform "free" ICG. Overall, fluorescence-guided pelvic nodal surgery underestimated the number of SNs in 60-80% of patients. Full Article
of Evaluation of dosimetry, quantitative methods and test-retest variability of 18F-PI-2620 PET for the assessment of tau deposits in the human brain By jnm.snmjournals.org Published On :: 2019-11-11T12:55:20-08:00 18F-PI-2620 is a next generation tau positron emission tomography (PET)-tracer that has demonstrated ability to image the spatial distribution of suspected tau pathology. The objective of this study was to assess the tracer biodistribution, dosimetry and quantitative methods of 18F-PI-2620 in the human brain. Full kinetic modelling approaches to quantify tau load were investigated. Non-invasive kinetic modeling approaches and semi-quantitative methods were evaluated against the full tracer kinetics. Finally, the reproducibility of PET measurements from test and retest scans was assessed. Methods: Three healthy controls (HC) and 4 Alzheimer disease (AD) subjects underwent two dynamic PET scans including arterial sampling. Distribution volume ratio (DVR) was estimated using full tracer kinetics (2 Tissue Compartment (2TC) models, Logan Graphical Analysis (LGA)) and non-invasive kinetic models (Non-Invasive Logan Graphical Analysis (NI-LGA) and the multilinear reference tissue model (MRTM2)). Standardized uptake value ratio (SUVR) was determined at different imaging windows after injection. Correlation between DVR and SUVR, effect size (Cohen’s d) and test-retest variability (TRV) were evaluated. Additionally, 6 HC subjects received one tracer administration and underwent whole-body PET for dosimetry calculation. Organ doses and the whole-body effective dose were calculated using OLINDA 2.0. Results: Strong correlation was found across different kinetic models (R2 >0.97) and between DVR(2TC) and SUVRs between 30 to 90 min with R2>0.95. Secular equilibrium was reached around 40 min post injection (p.i.) in most regions and subjects. The TRV and effect size for the SUVR across different regions was similar at 30-60 min (TRV=3.8%, d=3.80), 45-75 min (TRV=4.3%, d=3.77) and 60-90 min (TRV=4.9%, d=3.73) and increased at later time points. Elimination was via the hepatobiliary and urinary system. The whole-body effective dose was determined to be 33.3±2.1 μSv/MBq for an adult female and 33.1±1.4 μSv/MBq for an adult male with a 1.5 hour urinary bladder voiding interval. Conclusion: 18F-PI-2620 exhibits fast kinetics, suitable dosimetry and low TRV. DVR measured using the 2TC model with arterial sampling correlated strongly with DVR measured by NI-LGA, MRTM2 and SUVR. SUVR can be used for 18F-PI-2620 PET quantification of tau deposits avoiding arterial blood sampling. Static 18F-PI-2620 PET scans between 45-75min p.i. provide excellent quantification accuracy, large effect size and low TRV. Full Article
of Initial studies with [11C]vorozole positron emission tomography detect over-expression of intra-tumoral aromatase in breast cancer By jnm.snmjournals.org Published On :: 2019-11-22T10:43:33-08:00 Introduction: Aromatase inhibitors are the mainstay of hormonal therapy in estrogen receptor positive, postmenopausal breast cancer, although response rate is just over 50%. The goal of the present study was to validate and optimize positron emission tomography (PET) with 11C-vorozole for measuring aromatase expression in postmenopausal breast cancer. Methods: Ten newly diagnosed, postmenopausal women with biopsy confirmed breast cancer were administered 11C-vorozole intravenously and PET emission data collected between 40 – 90 minutes post-injection. Tracer injection and scanning were repeated 2 hours after ingestion of 2.5mg letrozole p.o. Mean and maximal standard uptake values and ratios to non-tumor tissue (SUVs, SUVRs) were calculated for tumor and non-tumor regions at baseline and after letrozole. Biopsy specimens from the same tumors were stained for aromatase using immunohistochemistry and evaluated for stain intensity and the percentage of immune-positive cells. Results: Seven of the 10 women (70%) demonstrated increased focal uptake of tracer (SUVR>1.1) coinciding with the mammographic location of the lesion. The other 3 women (30%) did not show increased uptake in the tumor (SUVR <1.0). All of the cases with SUVR above 1.1 had SUVs above 2.4 and there was no overlap in SUV between the two groups, with mean SUV in tumors overexpressing aromatase (SUVR>1.1) ranging from 2.47 to 13.6, while tumors not overexpressing aromatase (SUVR<1) ranged from 0.8 to 1.8. Pretreatment with letrozole reduced tracer uptake in the majority of subjects; although the %blocking varied across and within tumors. Tumors with high SUV in vivo also showed high staining intensity on IHC. Conclusion: PET with 11C-vorozole is a useful technique for measuring aromatase expression in individual breast lesions, enabling a non-invasive quantitative measurement of baseline and post-treatment aromatase availability in primary tumors and metastatic lesions. Full Article
of SUV25 and {micro}PERCIST: Precision Imaging of Response to Therapy in Co-Clinical FDG-PET Imaging of Triple Negative Breast Cancer (TNBC) Patient-Derived Tumor Xenografts (PDX) By jnm.snmjournals.org Published On :: 2019-11-22T10:43:33-08:00 Numerous recent works highlight the limited utility of established tumor cell lines in recapitulating the heterogeneity of tumors in patients. More realistic preclinical cancer models are thought to be provided by transplantable, patient-derived tumor xenografts (PDX). Inter- and intra-tumor heterogeneity of PDX, however, present several challenges in developing optimal quantitative pipelines to assess response to therapy. The objective of this work was to develop and optimize image metrics of FDG-PET to assess response to combination docetaxel/carboplatin therapy in a co-clinical trial involving triple negative breast cancer (TNBC) PDX. We characterize the reproducibility of SUV metrics to assess response to therapy and optimize a preclinical PERCIST (µPERCIST) paradigm to complement clinical standards. Considerations in this effort included variability in tumor growth rate and tumor size; solid tumor vs. tumor heterogeneity and necrotic phenotype; and optimal selection of tumor slice versus whole tumor. A test-retest protocol was implemented to optimize the reproducibility of FDG-PET SUV thresholds, SUVpeak metrics, and µPERCIST parameters. In assessing response to therapy, FDG-PET imaging was performed at baseline and +4 days following therapy. The reproducibility, accuracy, variability, and performance of imaging metrics to assess response to therapy were determined. We defined an index—"Quantitative Response Assessment Score (QRAS)"—to integrate parameters of prediction and precision, and thus aid in selecting optimal image metrics of response to therapy. Our data suggests that a threshold value of 25% (SUV25) of SUVmax was highly reproducible (<9% variability). Concordance and reproducibility of µPERCIST were maximized at α=0.7 and β=2.8 and exhibited high correlation to SUV25 measures of tumor uptake. QRAS scores favor SUV25 followed by SUVP14 as optimal metrics of response to therapy. Additional studies are warranted to fully characterize the utility of SUV25 and µPERCIST SUVP14 as image metrics of response to therapy across a wide range of therapeutic regiments and PDX models. Full Article
of Long term follow-up and outcomes of re-treatment in an expanded 50 patient single-center phase II prospective trial of Lutetium-177 (177Lu) PSMA-617 theranostics in metastatic castrate-resistant prostate cancer By jnm.snmjournals.org Published On :: 2019-11-22T10:43:33-08:00 Objectives: Lutetium-177 (177Lu)-PSMA-617 (LuPSMA) is a radioligand with high affinity for prostate specific membrane antigen (PSMA) enabling targeted beta-irradiation of prostate cancer. We have previously reported favorable activity with low toxicity in a prospective phase II trial involving 30 men with metastatic castrate-resistant prostate cancer (mCRPC). We now report their longer-term outcomes including a 20 patient extension cohort and outcomes of subsequent systemic treatments following completion of trial therapy. Methods: 50 patients with PSMA-avid mCRPC who had progressed after standard therapies received up to 4 cycles of LuPSMA every 6 weeks. Endpoints included PSA response (PCWG2), toxicity (CTCAE v4.03), imaging response, patient-reported health-related quality of life (QoL), progression-free and overall survival. We also describe, as a novel finding, outcomes of men who subsequently progressed and had further systemic therapies, including LuPSMA. Results: 75 men were screened to identify 50 patients eligible for treatment. Adverse prognostic features of the cohort included short median PSA doubling time (2.3 months) and extensive prior treatment including prior docetaxel (84%), cabazitaxel (48%), and abiraterone and/or enzalutamide (90%). The mean administered radioactivity was 7.5 GBq/cycle. PSA decline ≥ 50% was achieved in 32 of 50 patients (64%, 95% CI 50-77%), including 22 patients (44%, 95% CI 30-59%) with ≥ 80% decrease. Of 27 patients with measurable soft tissue disease, 15 (56%) achieved an objective response by RECIST 1.1. The most common toxicities attributed to LuPSMA were self-limiting G1-2 dry mouth (66%), transient G1-2 nausea (48%), G3-4 thrombocytopenia (10%) and G3 anemia (10%). Brief pain inventory severity and interference scores decreased at all time points including at the 3 month follow-up with a decrease of -1.2 (95% CI -0.5 to -1.9, P = 0.001) and 1.0 (95% CI -0.2 to -0.18, P = 0.013), respectively. At a median follow-up of 31.4 months, median OS was 13.3 months (95% CI 10.5-18.7) with a significantly longer survival of 18.4 months (95% CI 13.8-23.8) in patients achieving a PSA decline ≥ 50%. At progression following prior response, further LuPSMA was administered to 15 (30%) patients (median 2 cycles commencing 359 days from enrolment) with PSA decline ≥ 50% in 11 patients (73%). 4 of 21 patients (19%) receiving other systemic therapies upon progression experienced PSA decline ≥ 50%. There were no unexpected adverse events with LuPSMA re-treatment. Conclusion: This expanded 50 patient cohort of men with extensive prior therapy confirms our earlier report of high response rates, low toxicity and improved QoL with LuPSMA radioligand therapy. Upon progression, re-challenge LuPSMA demonstrated higher response rates than other systemic therapies. Full Article
of Diagnostic value of 68Ga-PSMA PET/CT for detection of PTEN expression in prostate cancer: a pilot study By jnm.snmjournals.org Published On :: 2019-11-22T10:43:33-08:00 Purpose: To explore the value of 68Ga-PSMA-PET/CT for detection of phosphatase and tensin homolog (PTEN) - loss prostate cancer (PCa). Methods: We retrospectively enrolled 75 patients who underwent multiparametric MRI (mpMRI) and 68Ga-PSMA PET/CT before radical prostatectomy. Lesions were outlined on pathological images and regions of interest were drawn on matched mpMRI and PET/CT images. Imaging parameters including average apparent diffusion coefficient (ADCmean) and maximum standardized uptake value (SUVmax) were derived. Immunohistochemical staining was carried out to evaluate the PTEN status. The diagnostic performance of imaging parameters was analyzed by receiver operating characteristics (ROC) analysis. A univariate logistic regression analyses were used to evaluate the association between clinical and imaging variables and PTEN status. Results: Totally, 103 lesions from 54 patients were analyzed. Of these lesions, 34 of 103 (33.0%) showed PTEN-loss status. Our study showed a strong association between SUVmax and PTEN-loss tumors both in the per-patient analysis (P < 0.01) and per-lesion analysis (P < 0.01), yielding the sensitivity and specificity of 0.80 and 0.77 in the per-patient analysis and 0.83 and 0.74 in the per-lesion analysis. Meanwhile, higher pathological PSMA expression was found in the PTEN-deficiency tumors. However, there was no significant difference between PTEN-loss tumors and PTEN-intact tumors using parameters including ADCmean (P > 0.05) and PI-RADS score (P > 0.05). Surprisingly, SUVmax was a significant predictor for detection of PTEN-loss tumors (odds ratio: 7.56, 95% confidence interval: 2.18-26.24, per-patient analysis; odds ratio: 13.66, 95% confidence interval: 4.32-43.24, per-lesion analysis). Conclusion: 68Ga-PSMA-PET/CT could effectively detect aggressive PTEN-loss tumors. Full Article
of Differential expression of glucose transporters and hexokinases in prostate cancer with a neuroendocrine gene signature: a mechanistic perspective for FDG imaging of PSMA-suppressed tumors By jnm.snmjournals.org Published On :: 2019-12-05T10:37:41-08:00 Purpose: Although the incidence of de novo neuroendocrine prostate cancer (NEPC) is rare, recent data suggests that low expression of prostate-specific membrane antigen (PSMA) is associated with a spectrum of neuroendocrine (NE) hallmarks and androgen receptor (AR)-suppression in prostate cancer (PC). Previous clinical reports indicate that PCs with a phenotype similar to NE tumors can be more amenable to imaging by 18F-Fluorodeoxyglucose (FDG) rather than PSMA-targeting radioligands. In this study, we evaluated the association between NE gene signature and FDG uptake-associated genes including glucose transporters (GLUTs) and hexokinases, with the goal of providing a genomic signature to explain the reported FDG-avidity of PSMA-suppressed tumors. Methods: Data mining approaches, cell lines and patient-derived xenograft (PDX) models were used to study the levels of 14 members of the SLC2A family (encoding GLUT proteins), 4 members of the hexokinase family (genes: HK1 to 3 and GCK) and PSMA (FOLH1 gene) following AR-inhibition and in correlation with NE hallmarks. Also, we characterize a NE-like PC (NELPC) subset among a cohort of primary and metastatic PC samples with no NE histopathology. We measured glucose uptake in a NE-induced in vitro model and a zebrafish model by non-radioactive imaging of glucose uptake using fluorescent glucose bioprobe, GB2-Cy3. Results: This work demonstrates that a NE gene signature associates with differential expression of genes encoding GLUT and hexokinase proteins. In NELPC, elevated expression of GCK (encoding glucokinase protein) and decreased expression of SLC2A12 correlated with earlier biochemical recurrence. In tumors treated with AR-inhibitors, high expression of GCK and low expression of SLC2A12 correlated with NE histopathology and PSMA gene suppression. GLUT12-suppression and amplification of glucokinase was observed in NE-induced PC cell lines and PDX models. A higher glucose uptake was confirmed in low-PSMA tumors using a GB2-Cy3 probe in a zebrafish model. Conclusion: NE gene signature in NEPC and NELPC associates with a distinct transcriptional profile of GLUTs and HKs. PSMA-suppression correlates with GLUT12-suppression and glucokinase-amplification. Alteration of FDG uptake-associated genes correlated positively with higher glucose uptake in AR and PSMA-suppressed tumors. Zebrafish xenograft tumor models are an accurate and efficient pre-clinical method for monitoring non-radioactive glucose uptake. Full Article
of Label-free Visualization of Early Cancer Hepatic Micrometastasis and Intraoperative Image-guided Surgery by Photoacoustic Imaging By jnm.snmjournals.org Published On :: 2019-12-05T10:37:41-08:00 Objectives: The detection of cancer micrometastasis for early diagnosis and treatment poses a great challenge for conventional imaging techniques. The aim of study is to evaluate the performance of photoacoustic imaging (PAI) in detecting hepatic micrometastases from melanoma in a very early stage and perform tumor resection by intraoperative photoacoustic image-guidance. Methods: In vivo studies were performed by following protocols approved by the Ethical Committee for Animal Research at Xiamen University. First, a B16 melanoma hepatic metastasis mouse model (n = 10) was established to study the development of micrometastases in vivo. Next, the hepatic metastasis mice models were imaged by scalable PAI instrument, ultrasound, 9.4 T high-resolution magnetic resonance imaging (MRI), positron emission tomography/computed tomography (PET/CT), and bioluminescence imaging. Photoacoustic images acquired with optical wavelengths spanning from 680 to 850 nm were spectrally unmixed by using a linear least-squares method to differentiate various components. Differences in the signal-to-background ratios among different modalities were determined with the two-tailed paired t test. The diagnosis results were assessed with histologic examinations. Excised liver samples from patients diagnosed with hepatic cancer were also examined to identify tumor boundary. In vivo metastatic melanoma removal in surgery was precisely guided by the portable PAI system. Results: PAI achieved as small as ~400 µm hepatic melanoma detection at a depth up to 7 mm in vivo, which could early detect small melanoma compared with ultrasound and MRI in mouse models. The signal ratio of tumor-to-liver acquired with PAI in micrometastases at 8 days (4.2 ± 0.2, n = 6) and 14 days (9.2 ± 0.4, n = 5) were significantly higher than those obtained with PET/CT (1.8 ± 0.1, n = 5 and 4.5 ± 0.2, n = 5, P <0.001 for both). Functional PAI provided dynamic oxygen saturation changes during tumor growth. The limit of detection was measured to be approximately 219 cells per microliter in vitro. We successfully performed intraoperative photoacoustic image-guided surgery in vivo using the rapid portable PAI system. Conclusion: Our findings offer a rapid and effective tool to noninvasively detect micrometastases and guide intraoperative resection as a complementary clinical imaging application. Full Article
of Quantitative test-retest measurement of 68Ga-PSMA-HBED-CC (PSMA-11) in tumor and normal tissue By jnm.snmjournals.org Published On :: 2019-12-05T10:37:42-08:00 The PET radiotracer 68Ga-PSMA-HBED-CC (68Ga-PSMA-11) shows potential as an imaging biomarker for recurrent and metastatic prostate cancer. The purpose of this study was to determine repeatability of 68Ga-PSMA-HBED-CC in a test-retest trial in subjects with metastatic prostate adenocarcinoma. Methods: Subjects with metastatic prostate cancer underwent two PET/CT scans with 68Ga-PSMA-HBED-CC within 14 days (mean 6 ± 4 d). Lesions in bone, nodes, prostate/bed, and visceral organs as well as representative normal tissues (salivary glands and spleen) were segmented separately by two readers. Absolute and percent differences in SUVmax and SUVmean were calculated for all test-retest regions. Repeatability was assessed using percentage difference, within-subject coefficient of variation (wCV), repeatability coefficient (RC), and Bland-Altman analysis. Results: 18 subjects were evaluated, 16 of which demonstrated local or metastatic disease on 68Ga-PSMA-HBED-CC PET/CT. A total of 136 lesions were segmented in bone (n = 99), nodes (n = 27), prostate/bed (n = 7), and viscera (n = 3). The wCV for SUVmax was 11.7% for bone lesions and 13.7% for nodes. The RC was ±32.5% SUVmax for bone lesions and ±37.9% SUVmax for nodal lesions, meaning 95% of the normal variability between two measurements will be within these numbers, so larger differences are likely attributable to true biological changes in tumor rather than normal physiologic or measurement variability. wCV in the salivary glands and spleen was 8.9% and 10.7% SUVmean, respectively. Conclusion: Repeatability measurements for PET/CT test-retest with 68Ga-PSMA-HBED-CC show a wCV 12-14% SUVmax and RC ±33-38% SUVmax in bone and nodal lesions. These estimates are an important aspect of 68Ga-PSMA-HBED-CC as a quantitative imaging biomarker. These estimates are similar to those reported for 18F-FDG, suggesting that 68Ga-PSMA-HBED-CC PET/CT may be useful in monitoring response to therapy. Full Article
of Imaging P-glycoprotein Induction at the Blood-Brain Barrier of a Beta-Amyloidosis Mouse Model with 11C-Metoclopramide PET By jnm.snmjournals.org Published On :: 2019-12-05T10:37:41-08:00 P-glycoprotein (ABCB1) plays an important role at the blood-brain barrier (BBB) in promoting the clearance of neurotoxic beta-amyloid (Aß) peptides from the brain into the blood. ABCB1 expression and activity were found to be decreased in the brains of Alzheimer disease (AD) patients. Treatment with drugs which induce cerebral ABCB1 activity may be a promising approach to delay the build-up of Aß deposits in the brain by enhancing the clearance of Aß peptides from the brain. The aim of this study was to investigate whether PET with the weak ABCB1 substrate radiotracer 11C-metoclopramide can measure ABCB1 induction at the BBB in a beta-amyloidosis mouse model (APP/PS1-21 mice) and in wild-type mice. Methods: Groups of wild-type and APP/PS1-21 mice aged 50 or 170 days underwent 11C-metoclopramide baseline PET scans or scans after intraperitoneal treatment with the rodent pregnane X receptor (PXR) activator 5-pregnen-3β-ol-20-one-16α-carbonitrile (PCN, 25 mg/kg) or its vehicle over 7 days. At the end of the PET scans, brains were harvested for immunohistochemical analysis of ABCB1 and Aß levels. In separate groups of mice, radiolabeled metabolites of 11C-metoclopramide were determined in plasma and brain at 15 min after radiotracer injection. As an outcome parameter of cerebral ABCB1 activity, the elimination slope of radioactivity washout from the brain (kE,brain) was calculated. Results: PCN treatment resulted in an increased clearance of radioactivity from the brain as reflected by significant increases in kE,brain (from +26% to +54% relative to baseline). Immunohistochemical analysis confirmed ABCB1 induction in the brains of PCN-treated APP/PS1-21 mice with a concomitant decrease in Aß levels. There was a significant positive correlation between kE,brain values and ABCB1 levels in the brain. In wild-type mice, a significant age-related decrease in kE,brain values was found. Metabolite analysis showed that the majority of radioactivity in the brain was composed of unmetabolized 11C-metoclopramide in all animal groups. Conclusion: 11C-metoclopramide can measure ABCB1 induction in the mouse brain without the need to consider an arterial input function and may find potential application in AD patients to non-invasively evaluate strategies to enhance the clearance properties of the BBB. Full Article
of 18F-Fluorodeoxyglucose Positron Emission Tomography / Computed Tomography in Left-Ventricular Assist Device Infection: Initial Results Supporting the Usefulness of Image-Guided Therapy By jnm.snmjournals.org Published On :: 2019-12-05T10:37:41-08:00 Background: Accurate definition of the extent and severity of left-ventricular assist device (LVAD) infection may facilitate therapeutic decision making and targeted surgical intervention. Here, we explore the value of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for guidance of patient management. Methods: Fifty-seven LVAD-carrying patients received 85 whole-body 18F-FDG PET/CT scans for the work-up of device infection. Clinical follow-up was obtained over a period of up to two years. Results: PET/CT showed various patterns of infectious involvement of the 4 LVAD components: driveline entry point (77% of cases), subcutaneous driveline path (87%), pump pocket (49%) and outflow tract (58%). Driveline smears revealed staphylococcus or pseudomonas strains as the underlying pathogen in a majority of cases (48 and 34%, respectively). At receiver-operating characteristics analysis, an 18F-FDG standardized uptake value (SUV) >2.5 was most accurate to identify smear-positive driveline infection. Infection of 3 or all 4 LVAD components showed a trend towards lower survival vs infection of 2 or less components (P = 0.089), while involvement of thoracic lymph nodes was significantly associated with adverse outcome (P = 0.001 for nodal SUV above vs below median). Finally, patients that underwent early surgical revision within 3 months after PET/CT (n = 21) required significantly less inpatient hospital care during follow-up when compared to those receiving delayed surgical revision (n = 11; p<0.05). Conclusion: Whole-body 18F-FDG PET/CT identifies the extent of LVAD infection and predicts adverse outcome. Initial experience suggests that early image-guided surgical intervention may facilitate a less complicated subsequent course. Full Article
of Radiation dosimetry and biodistribution of 68Ga-FAPI-46 PET imaging in cancer patients By jnm.snmjournals.org Published On :: 2019-12-13T13:35:10-08:00 Background: Targeting cancer-associated fibroblasts (CAFs) has become an attractive goal for diagnostic imaging and therapy as they can constitute as much as 90% of tumor mass. The serine protease fibroblast activation protein (FAP) is overexpressed selectively in CAFs, drawing interest in FAP as a stromal target. The quinoline-based FAP-inhibitor PET tracer, 68Ga-FAPI-04, has been previously shown to yield high tumor-to-background ratios (TBR) in patients with various cancers. Recent developments towards an improved compound for therapeutic application have identified FAPI-46 as a promising agent due to a longer tumor retention time in comparison with FAPI-04. Here we present a PET biodistribution and radiation dosimetry study of 68Ga-FAPI-46 in cancer patients. Methods: Six patients with different cancers underwent serial 68Ga-FAPI-46 PET/CT scans at three time points following radiotracer injection: 10 minutes, 1 hour, and 3 hours. The source organs consisted of the kidneys, bladder, liver, heart, spleen, bone marrow, uterus, and body remainder. OLINDA/EXM v.1.1 software was used to fit and integrate the kinetic organ activity data to yield total body and organ time-integrated activity coefficients/residence times and finally organ absorbed doses. Standardized uptake values (SUV) and TBR were generated from the contoured tumor and source organ volumes. Spherical volumes in muscle and blood pool were also obtained for TBR (Tumor SUVmax / Organ SUVmean). Results: At all timepoints, the highest organ SUVmax was observed in the liver. Tumor and organ mean SUVs decreased whereas TBRs in all organs but the uterus increased with time. The highest TBRs at 3 hours were observed with the bone marrow (31.1), muscle (22.8), heart (19.1), and spleen (19.0). Organs with the highest effective doses were the bladder wall (2.41E-03 mSv/MBq), followed by ovaries (1.15E-03 mSv/MBq) and red marrow (8.49E-04mSv/MBq). The average effective total body dose was 7.80E-03 mSv/MBq. Thus for administration of 200 MBq 68Ga-FAPI-46 the effective total body dose is 1.56 mSv ± 0.26 mSv, in addition to approximately 3.7 mSv from one low-dose CT scan done for attenuation correction. Conclusion: 68Ga-FAPI-46 PET/CT has a favorable dosimetry profile with an estimated whole body dose of 5.3 mSv for an administration of 200 MBq (5.4 mCi) of 68Ga-FAPI-46 (1.56± 0.26 mSv from the PET tracer and 3.7 mSv from one low-dose CT scan). The biodistribution study showed high TBRs increasing over time, suggesting high diagnostic performance and favorable tracer kinetics for potential therapeutic applications. Full Article
of What You See Is Not What You Get - On the Accuracy of Voxel-Based Dosimetry in Molecular Radiotherapy By jnm.snmjournals.org Published On :: 2019-12-20T13:25:42-08:00 Due to improvements in quantitative SPECT/CT, voxel-based dosimetry for radionuclide therapies has aroused growing interest as it promises the visualization of absorbed doses at a voxel level. In this work, SPECT/CT-based voxel-based dosimetry of a 3D printed 2-compartment kidney phantom was performed, and the resulting absorbed dose distributions were examined. Additionally, the potential of the PETPVC partial-volume correction tool was investigated. Methods: Both kidney compartments (70% cortex, 30% medulla) were filled with different activity concentrations and SPECT/CT imaging was performed. The images were reconstructed using varying reconstruction settings (iterations, subsets, and post-filtering). Based on these activity concentration maps, absorbed dose distributions were calculated with pre-calculated 177Lu voxel S values and an empirical kidney half-life. An additional set of absorbed doses was calculated after applying PETPVC for partial-volume correction of the SPECT reconstructions. Results: SPECT/CT imaging blurs the two discrete sub-organ absorbed dose values into a continuous distribution. While this effect is slightly improved by applying more iterations, it is enhanced by additional post-filtering. By applying PETPVC, the absorbed dose values are separated into 2 peaks. Although this leads to a better agreement between SPECT/CT-based and nominal values, considerable discrepancies remain. In contrast to the calculated nominal absorbed doses of 7.8/1.6 Gy (cortex/medulla), SPECT/CT-based voxel-level dosimetry resulted in mean absorbed doses ranging from 3.0-6.6 Gy (cortex) and 2.7-5.1 Gy (medulla). PETPVC led to improved ranges of 6.1-8.9 Gy (cortex) and 2.1-5.4 Gy (medulla). Conclusion: Our study shows that 177Lu quantitative SPECT/CT imaging leads to voxel-based dose distributions largely differing from the real organ distribution. SPECT/CT imaging and reconstruction deficiencies might directly translate into unrealistic absorbed dose distributions, thus questioning the reliability of SPECT-based voxel-level dosimetry. Therefore, SPECT/CT reconstructions should be adapted to ensure an accurate quantification of the underlying activity and, therefore, absorbed dose in a volume-of-interest of the expected object size (e.g. organs, organ sub-structures, lesions or voxels). As an example, PETPVC largely improves the match between SPECT/CT-based and nominal dose distributions. In conclusion, the concept of voxel-based dosimetry should be treated with caution. Specifically, it should be kept in mind that the absorbed dose distribution is mainly a convolved version of the underlying SPECT reconstruction. Full Article
of Quantitative 3D assessment of 68Ga-DOTATOC PET/MRI with diffusion-weighted imaging to assess imaging markers for gastroendopancreatic neuroendocrine tumors: Preliminary results By jnm.snmjournals.org Published On :: 2019-12-20T13:25:42-08:00 68Ga-DOTATOC-PET/MRI (68Gallium-DOTATOC-positron emission tomography/magnetic resonance imaging) combines the advantages of PET in the acquisition of metabolic-functional information with the high soft tissue contrast of MRI. Standardized uptake values (SUV) in tumors were suggested as a measure of somatostatin receptor expression. A challenge with receptor ligands is, that the distribution volume is confined to tissues with tracer-uptake, potentially limiting SUV quantification. In this study, different functional, three-dimensional (3D) SUV, apparent diffusion coefficient (ADC) parameters and arterial tumor enhancement were tested for the characterization of gastroendopancreatic neuroendocrine tumors (GEP-NET). Methods: For this single-center, cross-sectional study, 22 patients with 24 histologically confirmed GEP-NET lesions (15 men/7 women; median, 61 years, range, 43-81 years), who received hybrid 68Ga-DOTA-PET/MRI examinations at 3T between January 2017 and July 2019 met eligibility criteria. SUVs, tumor-to-background ratios (TBR), the total functional tumor volume (TFTV), ADCmean and ADCmin were measured based on volumes of interest (VOI) and examined with receiver operating characteristic analysis to determine cut-off values for differentiation between low and intermediate grade GEP-NET. Spearman’s rank correlation coefficients were used to assess correlations between functional imaging parameters. Results: The ratio of PET-derived SUVmean and diffusion-weighted imaging (DWI)-derived ADCmin was introduced as a combined variable to predict tumor grade, outperforming single predictors. Based on a threshold ratio of 0.03 to be exceeded, tumors could be classified as grade 2 with a sensitivity of 86% and specificity of 100%. SUV and functional ADC values as well as arterial contrast enhancement parameters showed non-significant and mostly negligible correlations. Conclusion: As receptor density and tumor cellularity appear to be independent, potentially complementary phenomena, the combined PET/MRI ratio SUVmean/ADCmin may be used as a novel biomarker, allowing to differentiate between grade 1 and 2 GEP-NET. Full Article
of Early Detection in a Mouse Model of Pancreatic Cancer by Imaging DNA Damage Response Signalling By jnm.snmjournals.org Published On :: 2019-12-20T13:25:42-08:00 Rationale: Despite its widespread use in oncology, the PET radiotracer 18F-FDG is ineffective for improving early detection of pancreatic ductal adenocarcinoma (PDAC). An alternative strategy for early detection of pancreatic cancer involves visualisation of high-grade pancreatic intraepithelial neoplasias (PanIN-3), generally regarded as the non-invasive precursors of PDAC. The DNA damage response is known to be hyper-activated in late-stage PanINs. Therefore, we investigated whether the SPECT imaging agent, 111In-anti-H2AX-TAT, allows visualisation of the DNA damage repair marker H2AX in PanIN-3s in an engineered mouse model of PDAC, to facilitate early detection of PDAC. Methods: Genetically engineered KPC mice (KRasLSL.G12D/+; p53LSL.R172H/+; PdxCre) were imaged with 18F-FDG and 111In-anti-H2AX-TAT. PanIN/PDAC presence visualised by histology was compared with autoradiography and immunofluorescence. Separately, the survival of KPC mice imaged with 111In-anti-H2AX-TAT was evaluated. Results: In KPC mouse pancreata, H2AX expression was increased in high-grade PanINs, but not in PDAC, corroborating earlier results obtained from human pancreas sections. Uptake of 111In-anti-H2AX-TAT, but not 111In-IgG-TAT or 18F-FDG, within the pancreas was positively correlated with the age of KPC mice, which was correlated with the number of high-grade PanINs. 111In-anti-H2AX-TAT localises preferentially in high-grade PanIN lesions, but not in established PDAC. Younger, non-tumour-bearing KPC mice that show uptake of 111In-anti-H2AX-TAT in the pancreas survive significantly shorter than mice with physiological 111In-anti-H2AX-TAT uptake. Conclusion: 111In-anti-H2AX-TAT imaging allows non-invasive detection of DNA damage repair signalling upregulation in pre-invasive PanIN lesions and is a promising new tool to aid in the early detection and staging of pancreatic cancer. Full Article
of Head to head prospective comparison of quantitative lung scintigraphy and segment counting in predicting pulmonary function of lung cancer patients undergoing video-assisted thoracoscopic lobectomy By jnm.snmjournals.org Published On :: 2019-12-20T13:25:42-08:00 Prediction of post-operative pulmonary function in lung cancer patients before tumor resection is essential for patient selection for surgery and is conventionally done with a non-imaging segment counting method (SC) or a two-dimensional planar lung perfusion scintigraphy (PS). The purpose of this study was to compare quantitative analysis of PS to single photon emission computed tomography/computed tomography (SPECT/CT) and to estimate the accuracy of SC, PS and SPECT/CT in predicting post-operative pulmonary function in patients undergoing lobectomy. Methods: Seventy-five non-small cell lung cancer (NSCLC) patients planned for lobectomy were prospectively enrolled (68% males, average age 68.1±8 years ). All patients completed pre-operative forced expiratory volume capacity (FEV1), diffusing capacity of the lung for carbon monoxide (DLCO), Tc99m-MAA lung perfusion scintigraphy with PS and SPECT/CT quantification. A subgroup of 60 patients underwent video-assisted thoracoscopic (VATS) lobectomy and measurement of post-operative FEV1 and DLCO. Relative uptake of the lung lobes estimated by PS and SPECT/CT were compared. Predicted post-operative FEV1 and DLCO were derived from SC, PS and SPECT/CT. Prediction results were compared between the different methods and the true post-operative measurements in patients who underwent lobectomy. Results: Relative uptake measurements differed significantly between PS and SPECT/CT in right lung lobes, with a mean difference of -8.2±3.8, 18.0±5.0 and -11.5±6.1 for right upper, middle and lower lobes respectively (p<0.001). The differences between the methods in the left lung lobes were minor with a mean difference of -0.4±4.4 (p>0.05) and -2.0±4.0 (p<0.001) for left upper and lower lobes respectively. No significant difference and strong correlation (R=0.6-0.76, p<0.001) were found between predicted post-operative lung function values according to SC, PS, SPECT/CT and the actual post-operative FEV1 and DLCO. Conclusion: Although lobar quantification parameters differed significantly between PS and SPECT/CT, no significant differences were found between the predicted post-operative lung function results derived from these methods and the actual post-operative results. The additional time and effort of SPECT/CT quantification may not have an added value in patient selection for surgery. SPECT/CT may be advantageous in patients planned for right lobectomies but further research is warranted. Full Article
of 177Lu-NM600 targeted radionuclide therapy extends survival in syngeneic murine models of triple-negative breast cancer By jnm.snmjournals.org Published On :: 2019-12-20T13:25:42-08:00 Triple negative breast cancer (TNBC) remains the most aggressive subtype of breast cancer leading to the worst prognosis. Because current therapeutic approaches lack efficacy, there is a clinically unmet need for effective treatment alternatives. Herein, we demonstrate a promising strategy utilizing a tumor-targeting alkylphosphocholine (NM600) radiolabeled with 177Lu for targeted radionuclide therapy (TRT) of TNBC. In two murine syngeneic models of TNBC, we confirmed excellent tumor targeting and rapid normal tissue clearance of the PET imaging analog 86Y-NM600. Based on longitudinal PET/CT data acquired with 86Y-NM600, we estimated the dosimetry of therapeutic 177Lu-NM600, which showed larger absorbed doses in the tumor compared to normal tissues. Administration of 177Lu-NM600 resulted in significant tumor growth inhibition and prolonged overall survival in mice bearing syngeneic 4T07 and 4T1 tumors. Complete response was attained in 60% of 4T07 bearing mice, but animals carrying aggressive 4T1 tumor grafts succumbed to metastatic progression. The injected activities used for treatment (9.25 and 18.5 MBq) were well tolerated, and only mild transient cytopenia was noted. Overall, our results suggest that 177Lu-NM600 TRT has potential for treatment of TNBC and merits further exploration in a clinical setting. Full Article
of Hyper-progressive Disease in Patients With Non-Small Cell Lung Cancer Treated With Checkpoint Inhibitors: The Role of 18F-FDG PET/CT By jnm.snmjournals.org Published On :: 2019-12-20T13:25:42-08:00 Introduction: A new pattern of response, so-called hyper-progressive disease (HPD), is emerging during treatment with immune checkpoint inhibitors (ICI). Our aim was to investigate the prevalence of such phenomenon and to assess its association with clinical variables and metabolic parameters by 18F-fludeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). Methods: Data from 50 patients (34 male, 16 female, median age 73) with non-small cell lung carcinoma (NSCLC) and treated with ICI were prospectively collected. All patients underwent contrast-enhanced CT, 18F-FDG PET/CT, and complete peripheral blood sample at baseline before ICI. HPD was defined according to clinical and radiologic criteria. Because of the rapid disease progression or worsening of clinic conditions, radiologic response assessment was available for 46 patients. OS were analyzed using the Kaplan–Meier method and the log-rank test. A Cox proportional hazards regression analysis was used to evaluate factors independently associated with OS. Median follow-up was 12.4 months (9.7-15.2 months). Results: We identified the following response categories: 10 cases as complete/partial response (CR/PR), 17 cases with stable disease (SD), 5 patients with progressive disease (PD), and 14 with HPD. Among metabolic parameters we observed a statistically significant association between HPD status and tumor burden, expressed by both MTV (756.1ml for HPD vs 475.6ml for non-HPD, P = 0.011) and TLG (287.3 for HPD vs 62.1 for non-HPD, P = 0.042). Among clinical variables, 12/14 patients (85.7%) within the HPD group compared with 8/32 patients (25%) in the non-HDP group had more than two metastatic sites (p<0.001). In addition, the derived neutrophil-to-lymphocyte ratio (dNLR) and platelet counts was significantly associated with HPD status (P = 0.038, P = 0.025, respectively). Survival analysis showed a median OS of 4 months for HPD group compared with 15 months within non-HPD patients (P = 0.003). Likewise, median OS was significantly different when we considered all the response categories: CR/PR, SD, PD, and HPD (P = 0.001). Finally, Multivariate analysis identified MTV and dNLR as independent predictors for OS. Conclusion: Our results suggest that the use of ICI might represent a concern in patients with high metabolic tumor burden and inflammatory indexes at baseline. However Additional studies are needed. Full Article
of Management of patients with renal failure undergoing dialysis during 131I therapy for thyroid cancer By jnm.snmjournals.org Published On :: 2020-01-10T04:59:09-08:00 Objectives: Radioactive iodine (131I) therapy may be used to treat thyroid cancer in end-stage renal disease patients who undergo hemodialysis. Because iodine predominantly utilizes renal clearance, treatment management in hemodialysis patients may be problematic, and no formal recommendations on hemodialysis currently exist. This work details our experience with treating thyroid cancer with iodine in chronic renal failure patients who require hemodialysis and details the therapeutic dosimetry results obtained during treatment to ensure that the dose to the bone marrow (BM) was acceptable. Methods: We treated 6 patients in the metabolic radiotherapy unit after thyroid stimulation. Two hemodialysis sessions in the metabolic radiotherapy unit were performed at 42 and 90 hours after radiopharmaceutical administration. BM toxicity was estimated with activity measurements from blood samples and with whole-body measurements that were regularly repeated during hospitalization and measured with a gamma counter. The patients underwent thyroid and hematologic monitoring to assess treatment efficacy and therapeutic toxicity in the short, medium and long term. Results: Whole-body activity was reduced on average by 66.7% [60.1-71.5] after the first dialysis session and by 53.3% [30.4-67.8] after the second. The mean estimated total absorbed dose to the BM was 0.992 Gy for all patients [0.431 – 2.323]. We did not observe any significant hematologic toxicity, and the clinical, biological and ultrasound test results confirmed the success of ablative treatment for the majority of patients. Conclusion: An approximately 30% reduction from the nominal dose in the amount of 131I activity for hemodialysis patients with thyroid cancer appears to strike an appropriate balance between the absence of BM toxicity and therapeutic efficacy. To avoid overirradiation, we recommend pretherapeutic dosimetry studies for metastatic patients to calculate the amount of activity to be administered as well as dosimetry monitoring during the hemodialysis sessions performed after therapeutic dose administration and under the same conditions. Full Article
of Targeted optical imaging of the glucagon-like peptide 1 receptor using exendin-4-IRDye800CW By jnm.snmjournals.org Published On :: 2020-01-10T04:59:09-08:00 Rationale: The treatment of choice for insulinomas and focal lesions in congenital hyperinsulinism (CHI) is surgery. However, intra-operative detection can be challenging. This could be overcome with intra-operative fluorescence imaging, which provides real-time lesion detection with a high spatial resolution. Here, a novel method for targeted near-infrared (NIR) fluorescence imaging of glucagon-like peptide 1 receptor (GLP-1R) positive lesions, using the GLP-1 agonist exendin-4, labeled with IRDye800CW, was examined in vitro and in vivo. Methods: A competitive binding assay was performed using Chinese hamster lung (CHL) cells transfected with the GLP-1R. Tracer biodistribution was determined in BALB/c nude mice bearing subcutaneous CHL-GLP-1R xenografts. In vivo NIR fluorescence imaging of CHL-GLP-1R xenografts was performed. Localization of the tracer in the pancreatic islets of BALB/c nude mice was examined using fluorescence microscopy. Laparoscopic imaging was performed to detect the fluorescent signal of the tracer in the pancreas of mini pigs. Results: Exendin-4-IRDye800CW binds the GLP-1R with an IC50 value of 3.96 nM. The tracer accumulates in CHL-GLP-1R xenografts. Subcutaneous CHL-GLP-1R xenografts were visualized using in vivo NIR fluorescence imaging. The tracer accumulates specifically in the pancreatic islets of mice and a clear fluorescent signal was detected in the pancreas of mini pigs. Conclusion: These date provide the first in vivo evidence of the feasibility of targeted fluorescence imaging of GLP-1R positive lesions. Intra-operative lesion delineation using exendin-4-IRDye800CW could benefit open as well as laparoscopic surgical procedures for removal of insulinomas and focal lesions in CHI. Full Article
of Evaluation of 11C-NR2B-SMe and its Enantiomers as PET Radioligands for Imaging the NR2B Subunit within the NMDA Receptor Complex in Rats By jnm.snmjournals.org Published On :: 2020-01-10T04:59:09-08:00 [S-Methyl-11C](±)-7-methoxy-3-(4-(4-(methylthio)phenyl)butyl)-2,3,4,5-tetrahydro-1H-benzo[d]azepin-1-ol (11C-NR2B-SMe) and its enantiomers were synthesized as candidates for imaging the NR2B subunit within the N-methyl-D-aspartate receptor with positron emission tomography (PET). Methods: Brains were scanned with PET for 90 min after intravenous injection of one of the candidate radioligands into rats. To detect any NR2B specific binding of radioligand in brain, various pre-blocking or displacing agents were evaluated for their impact on the PET brain imaging data. Radiometabolites from brain and other tissues were measured ex vivo and in vitro. Results: Each radioligand gave high early whole brain uptake of radioactivity, followed by a brief fast decline and then a slow final decline. 11C-(S)-NR2B-SMe was studied extensively. Ex vivo measurements showed that radioactivity in rat brain at 30 min after radioligand injection was virtually unchanged radioligand. Only less lipophilic radiometabolites appeared in plasma. High-affinity NR2B ligands, Ro-25-6981, ifenprodil, and CO10124, showed increasing preblock of whole brain radioactivity retention with increasing dose (0.01 to 1.25 mg/kg, i.v.). Five 1 antagonists (FTC146, BD1407, F3, F4, and NE100) and four 1 agonists ((+)-pentazocine, (±)-PPCC, PRE-084, (+)-SKF10047) were ineffective preblocking agents, except FTC146 and F4 at high dose. Two potent 1 receptor agonists, TC1 and SA4503, showed dose-dependent preblocking effects in the presence or absence of pharmacological 1 receptor blockade with FTC146. Conclusion: 11C-(S)-NR2B-SMe has adequate NR2B-specific PET signal in rat brain to warrant further evaluation in higher species. TC1 and SA4503 likely have off-target binding to NR2B in vivo. Full Article
of Repeatability of Quantitative 18F-DCFPyL PET/CT Measurements in Metastatic Prostate Cancer. By jnm.snmjournals.org Published On :: 2020-01-10T04:59:09-08:00 Quantitative evaluation of radiolabeled Prostate-Specific Membrane Antigen (PSMA) PET scans may be used to monitor treatment response in patients with prostate cancer (PCa). To interpret longitudinal differences in PSMA uptake, the intrinsic variability of tracer uptake in PCa lesions needs to be defined. The aim of this study was to investigate the repeatability of quantitative 18F-DCFPyL (a second generation 18F-PSMA-ligand) PET/CT measurements in patients with PCa. Methods: Twelve patients with metastatic PCa were prospectively included, of which 2 were excluded from final analyses. Patients received two whole-body 18F-DCFPyL PET/CT scans (median dose 317 MBq; uptake time 120 min), within median 4 days (range 1-11 days). After semi-automatic (isocontour-based) tumor delineation, the following lesion-based metrics were derived: Tumor-to-Blood ratio (TBRmean, TBRpeak, and TBRmax), Standardized Uptake Value (SUVmean, SUVpeak, SUVmax, normalized to bodyweight), tumor volume, and total lesion tracer uptake (TLU). Additionally, patient-based Total Tumor Volume (sum of PSMA-positive tumor volumes; TTV) and Total Tumor Burden (sum of all lesion TLUs; TTB) were derived. Repeatability was analyzed using repeatability coefficients (RC) and intra-class correlations (ICC). Additionally, the effect of point spread function (PSF) image reconstruction on the repeatability of uptake metrics was evaluated. Results: In total, 36 18F-DCFPyL PET positive lesions were analyzed (up to 5 lesions per patient). RCs of TBRmean, TBRpeak, and TBRmax were 31.8%, 31.7%, and 37.3%, respectively. For SUVmean, SUVpeak, SUVmax the RCs were 24.4%, 25.3% and 31.0%, respectively. All ICC were ≥0.97. Tumor volume delineations were well repeatable, with RC 28.1% for individual lesion volumes and RC 17.0% for TTV. TTB had a RC of 23.2% and 33.4%, when based on SUVmean and TBRmean, respectively. Small lesions (<4.2mL) had worse repeatability for volume measurements. The repeatability of SUVpeak, TLU, and all patient-level metrics were not affected by PSF-reconstruction. Conclusion: 18F-DCFPyL uptake measurements are well repeatable and can be used for clinical validation in future treatment response assessment studies. Patient-based TTV may be preferred for multicenter studies since its repeatability was both high and robust to different image reconstructions. Full Article
of Light-induced radiosynthesis of 89ZrDFO-azepin-onartuzumab for imaging the hepatocyte growth factor receptor By jnm.snmjournals.org Published On :: 2020-01-10T04:59:09-08:00 Methods that provide rapid access to radiolabeled antibodies are vital in the development of diagnostic and radiotherapeutic agents for positron emission tomography (PET) or radioimmunotherapy. The human hepatocyte growth factor receptor (c-MET) signaling pathway is dysregulated in a number of malignancies including gastric cancer, and is an important biomarker in drug discovery. Here, we used a photoradiochemical approach to produce 89Zr-radiolabeled onartuzumab (a monovalent, anti-human c-MET antibody), starting directly from the fully formulated drug (MetMAb). Methods: Simultaneous 89Zr-radiolabeling and protein conjugation was performed in one-pot reactions containing 89Zr-oxalate, the photoactive chelate DFO-aryl azide (DFO-ArN3) and MetMAb to give 89ZrDFO-azepin-onartuzumab. As a control, 89ZrDFO-Bn-NCS-onartuzumab was prepared via a conventional two-step process using pre-purified onartuzumab and DFO-Bn-NCS. Radiotracers were purified by using size-exclusion methods and evaluated by radiochromatography. Radiochemical stability was studied in human serum and immunoreactivity was determined by cellular binding assays using MKN-45 gastric carcinoma cells. PET imaging at multiple time points (0–72 h) was performed in female athymic nude mice bearing subcutaneous MKN-45 xenografts. Biodistribution experiments were performed after the final image. Tumor specificity of 89ZrDFO-azepin-onartuzumab was assessed by competitive inhibition (blocking) studies. Results: Initial photoradiosynthesis experiments produced 89ZrDFO-azepin-onartuzumab in <15 min. with an isolated decay-corrected radiochemical yield (RCY) of 24.8%, a radiochemical purity (RCP) ~90% and a molar activity (Am) of ~1.5 MBq nmol-1. Reaction optimization improved the radiochemical conversion (RCC) of 89ZrDFO-azepin-onartuzumab to 56.9±4.1% (n = 3), with isolated RCYs of 41.2±10.6% (n = 3), and RCPs >90%. Conventional methods produced 89ZrDFO-Bn-NCS-onartuzumab with isolated RCY >97%, RCP >97% and Am ~14.0 MBq nmol-1. Both radiotracers were immunoreactive and stable in human serum. PET imaging and biodistribution studies showed high tumor uptake for both radiotracers. By 72 h, tumor and liver uptake reached 15.37±5.21 %ID g-1, 6.56±4.03 %ID g-1, respectively for 89ZrDFO-azepin-onartuzumab (n = 4), and 21.38±11.57 %ID g-1 and 18.84±6.03 %ID g-1 for 89ZrDFO-Bn-NCS-onartuzumab (n = 4). Blocking experiments gave a statistically significant reduction in tumor uptake (6.34±0.47 %ID g-1) of 89ZrDFO-azepin-onartuzumab (n = 4). Conclusion: Experiments demonstrate that photoradiosynthesis is a viable alternative approach for producing 89Zr-radiolabeled antibodies direct in protein formulation buffer which reduces protein aggregation and liver uptake. Full Article
of Impact of 68Ga-PSMA-11 PET/CT on Staging and Management of Prostate Cancer Patients in Various Clinical Settings: A Prospective Single Center Study By jnm.snmjournals.org Published On :: 2020-01-10T04:59:09-08:00 The impact of prostate specific membrane antigen (PSMA) PET/CT on management of prostate cancer (PCa) patients with biochemical recurrence (BCR) is well-established. However, whether and how PSMA PET/CT affects the management of patients undergoing scans for other clinical indications remains unknown. The goal of this study was to determine the impact of 68Ga-PSMA-11 PET/CT on initial and subsequent management decisions in a cohort of PCa patients referred for various indications ("basket trial") excluding the two main classical indications: BCR and presurgical staging. Methods: This was a prospective study of 197 patients that aimed to determine the impact of 68Ga-PSMA-11 PET/CT on PCa stage and management. Indications for PSMA PET/CT were: initial staging of non-surgical candidates (30 patients) and re-staging after definitive treatment (n = 168). The re-staging cohort comprised: patients re-staged with known advanced metastatic disease (n = 103), after androgen deprivation therapy only (n = 16), after surgery with serum PSA levels <0.2 ng/ml (n = 13), after radiation therapy (RT) not meeting the Phoenix criteria (n = 22) and after other primary local treatments [i.e. high-intensity focused ultrasound (HIFU), focal laser ablation, cryoablation, hyperthermia or irreversible electroporation] (n = 13). Patients with BCR and candidates for curative surgery were excluded. Impact on management was assessed using pre- and post-PET questionnaires completed by referring physicians, electronic chart review and/or patient telephone encounters. Results: PSMA PET/CT changed disease stage in 135/197 (69%) patients (38% up-stage, 30% down-stage and no changes in stage in 32%). Management was affected in 104/182 (57%) patients. Specifically, PSMA PET/CT impacted management of patients who were re-staged after RT without meeting the Phoenix criteria for BCR, after other definitive local treatments and with advanced metastatic disease in 13/18 (72%), 8/12 (67%) and 59/96 (61%), respectively. Conclusion: PSMA PET/CT has a profound impact on stage and management of PCa patients outside of the two main classical indications (BCR and presurgical staging) across all examined clinical scenarios. Full Article
of Projection-space implementation of deep learning-guided low-dose brain PET imaging improves performance over implementation in image-space By jnm.snmjournals.org Published On :: 2020-01-10T04:59:09-08:00 Purpose: To assess the performance of full dose (FD) positron emission tomography (PET) image synthesis in both image and projection space from low-dose (LD) PET images/sinograms without sacrificing diagnostic quality using deep learning techniques. Methods: Clinical brain PET/CT studies of 140 patients were retrospectively employed for LD to FD PET conversion. 5% of the events were randomly selected from the FD list-mode PET data to simulate a realistic LD acquisition. A modified 3D U-Net model was implemented to predict FD sinograms in the projection-space (PSS) and FD images in image-space (PIS) from their corresponding LD sinograms/images, respectively. The quality of the predicted PET images was assessed by two nuclear medicine specialists using a five-point grading scheme. Quantitative analysis using established metrics including the peak signal-to-noise ratio (PSNR), structural similarity index metric (SSIM), region-wise standardized uptake value (SUV) bias, as well as first-, second- and high-order texture radiomic features in 83 brain regions for the test and evaluation dataset was also performed. Results: All PSS images were scored 4 or higher (good to excellent) by the nuclear medicine specialists. PSNR and SSIM values of 0.96 ± 0.03, 0.97 ± 0.02 and 31.70 ± 0.75, 37.30 ± 0.71 were obtained for PIS and PSS, respectively. The average SUV bias calculated over all brain regions was 0.24 ± 0.96% and 1.05 ± 1.44% for PSS and PIS, respectively. The Bland-Altman plots reported the lowest SUV bias (0.02) and variance (95% CI: -0.92, +0.84) for PSS compared with the reference FD images. The relative error of the homogeneity radiomic feature belonging to the Grey Level Co-occurrence Matrix category was -1.07 ± 1.77 and 0.28 ± 1.4 for PIS and PSS, respectively Conclusion: The qualitative assessment and quantitative analysis demonstrated that the FD PET prediction in projection space led to superior performance, resulting in higher image quality and lower SUV bias and variance compared to FD PET prediction in the image domain. Full Article
of 11C-(+)-PHNO Trapping Reversibility for Quantitative PET Imaging of Beta-Cell-Mass in Patients with Type-1 Diabetes By jnm.snmjournals.org Published On :: 2020-01-10T04:59:09-08:00 Full Article
of SUVmax-V for assessing treatment response in FDG-PET Imaging of Patient-Derived Tumor Xenografts involving Triple-Negative Breast Cancer By jnm.snmjournals.org Published On :: 2020-01-10T04:59:09-08:00 Full Article
of Individual mapping of innate immune cell activation is a candidate marker of patient-specific trajectories of disability worsening in Multiple Sclerosis By jnm.snmjournals.org Published On :: 2020-01-31T13:36:41-08:00 Objective: To develop a novel approach to generate individual maps of white matter (WM) innate immune cell activation using 18F-DPA-714 translocator protein (TSPO) positron emission tomography (PET), and to explore the relationship between these maps and individual trajectories of disability worsening in patients with multiple sclerosis (MS). Methods: Patients with MS (n = 37), whose trajectories of disability worsening over the 2 years preceding study entry were calculated, and healthy controls (n = 19) underwent magnetic resonance magnetic and 18F-DPA-714 PET. A threshold of significant activation of 18F-DPA-714 binding was calculated with a voxel-wise randomized permutation-based comparison between patients and controls, and used to classify each WM voxel in patients as characterized by a significant activation of innate immune cells (DPA+) or not. Individual maps of innate immune cell activation in the WM were employed to calculate the extent of activation in WM regions-of-interests and to classify each WM lesion as "DPA-active", "DPA-inactive" or "unclassified". Results: Compared with the WM of healthy controls, patients with MS had a significantly higher percentage of DPA+ voxels in the normal-appearing WM, (NAWM in patients=24.9±9.7%; WM in controls=14.0±7.8%, p<0.001). In patients with MS, the percentage of DPA+ voxels showed a significant increase from NAWM, to perilesional areas, T2 hyperintense lesions and T1 hypointense lesions (38.1±13.5%, 45.0±17.9%, and 51.9±22.9%, respectively, p<0.001). Among the 1379 T2 lesions identified, 512 were defined as DPA-active and 258 as DPA-inactive. A higher number of lesions classified as DPA-active (OR=1.13, P = 0.009), a higher percentage of DPA+ voxels in the NAWM (OR=1.16, P = 0.009) and in T1-spin-echo lesions (OR=1.06, P = 0.036), were significantly associated with a retrospective more severe clinical trajectory in patients with MS. Conclusion: A more severe trajectory of disability worsening in MS is associated with an innate immune cells activation inside and around WM lesions. 18F-DPA-714 PET may provide a promising biomarker to identify patients at risk of severe clinical trajectory. Full Article
of Demarcation of Sepsis-Induced Peripheral and Central Acidosis with pH-Low Insertion Cyclic (pHLIC) Peptide By jnm.snmjournals.org Published On :: 2020-01-31T13:36:41-08:00 Acidosis is a key driver for many diseases, including cancer, sepsis, and stroke. The spatiotemporal dynamics of dysregulated pH across disease remains elusive and current diagnostic strategies do not provide localization of pH alterations. We sought to explore if PET imaging using hydrophobic cyclic peptides that partition into the cellular membrane at low extracellular pH (denoted as "pHLIC") can permit accurate in vivo visualization of acidosis. Methods: Acid-sensitive cyclic peptide c[E4W5C] pHLIC was conjugated to bifunctional maleimide-NO2A and radiolabeled with copper-64 (t1/2 = 12.7 h). C57BL/6J mice were administered LPS (15 mg/kg) or saline (vehicle) and serially imaged with [64Cu]Cu-c[E4W5C] over 24 h. Ex vivo autoradiography was performed on resected brain slices and subsequently stained with cresyl violet to enable high-resolution spatial analysis of tracer accumulation. A non- pH-sensitive cell-penetrating control peptide (c[R4W5C]) was used to confirm specificity of [64Cu]Cu-c[E4W5C]. CD11b (macrophage/microglia) and TMEM119 (microglia) immunostaining was performed to correlate extent of neuroinflammation with [64Cu]Cu-c[E4W5C] PET signal. Results: [64Cu]Cu-c[E4W5C] radiochemical yield and purity was >95% and >99% respectively, with molar activity >0.925 MBq/nmol. Significantly increased [64Cu]Cu-c[E4W5C] uptake was observed in LPS-treated mice (vs. vehicle) within peripheral tissues including blood, lungs, liver, and small intestines (P < 0.001-0.05). Additionally, there was significantly increased [64Cu]Cu-c[E4W5C] uptake in the brains of LPS-treated animals. Autoradiography confirmed increased uptake in the cerebellum, cortex, hippocampus, striatum, and hypothalamus of LPS-treated mice (vs. vehicle). Immunohistochemical (IHC) analysis revealed microglial/macrophage infiltrate, suggesting activation in brain regions containing increased tracer uptake. [64Cu]Cu-c[R4W5C] demonstrated significantly reduced uptake in the brain and periphery of LPS mice compared to the acid-mediated [64Cu]Cu-c[E4W5C] tracer. Conclusion: Here, we demonstrate that a pH-sensitive PET tracer specifically detects acidosis in regions associated with sepsis-driven pro-inflammatory responses. This study suggests that [64Cu]Cu-pHLIC is a valuable tool to noninvasively assess acidosis associated with both central and peripheral innate immune activation. Full Article
of Improved Alignment of PET and CT Images in Whole-Body PET/CT in Cases of Respiratory Motion During CT By jnm.snmjournals.org Published On :: 2020-01-31T13:36:41-08:00 Respiratory motion during the CT and PET parts of a PET/CT scan leads to imperfect alignment of anatomical features seen by the two modalities. In this work, we concentrate on the effects of motion during CT. We propose a novel approach for improving the alignment. Methods: Respiratory waveform data were gathered during the CT and PET parts of 28 PET/CT scans of cancer patients with 40 lesions up to 3 cm size in the lung or upper abdomen. PET list-mode data were reconstructed by three reconstruction methods: PET/static, PET/EX or end of expiration (OncoFreeze), and a novel PET/matched method that used both waveforms. The three methods were compared. The distance between tumor positions in PET and CT were characterized in visual interpretation by physicians as well as quantitatively. Tumor standardized uptake values (SUVmax and SUVpeak) were determined relative to SUV based on the static method. Image noise was evaluated in the liver and compared to PET/static. Results: In visual interpretation, the rate of good alignment was 13/21, 13/23 and 18/21 for PET/static, PET/EX and PET/matched methods, respectively, and the mean PET-CT distances were 3.5, 5.1 and 2.8 mm. In visual comparison with PET/EX, the rate of good alignment was increased in 1/10 and 7/10 cases for PET/static and PET/matched. SUVmax was on average 21% higher than PET/static when either PET/EX or PET/matched was used. SUVpeak was 12% higher. Image noise in the liver was 15% higher than static for the PET/EX method, and 40% higher for PET/matched; that is, noise was much lower than in gated PET. Conclusion: Acquiring respiratory waveforms both in PET (as in the current state of the art) and in CT (an unusual key step in this approach) has the potential to improve the alignment of PET and CT images. A proposed method for using this information was tested. Improved alignment was demonstrated. Full Article
of 64Cu-DOTATATE PET/CT for Imaging Patients with Known or Suspected Somatostatin Receptor-Positive Neuroendocrine Tumors: Results of the First US Prospective, Reader-Blinded Clinical Trial By jnm.snmjournals.org Published On :: 2020-01-31T13:36:41-08:00 Studies demonstrate that the investigational 64Cu-DOTATATE radiopharmaceutical may provide diagnostic and logistical benefits over available imaging agents for patients with somatostatin receptor (SSTR)-positive neuroendocrine tumors (NETs). Accordingly, we aimed to prospectively determine the lowest dose of 64Cu-DOTATATE that facilitates diagnostic quality scans and evaluated the diagnostic performance and safety in a phase III study of patients with SSTR-expressing NETs. Methods: A dose-ranging study was conducted in 12 patients divided into 3 dose groups (111 MBq [3.0 mCi], 148 MBq [4.0 mCi], and 185 MBq [5.0 mCi] ± 10%) to determine the lowest dose of 64Cu-DOTATATE that produced diagnostic quality PET/CT images. Using the 64Cu-DOTATATE dose identified in the dose-ranging study, 3 independent nuclear medicine physicians who were blinded to all clinical information read PET/CT scans from 21 healthy volunteers and 42 NET-positive patients to determine those with "Disease" and "No Disease," as well as "Localized" versus "Metastatic" status. Blinded-reader evaluations were compared to a patient-specific standard of truth (SOT), which was established by an independent oncologist who used all previously available pathology, clinical, and conventional imaging data. Diagnostic performance calculated for 64Cu-DOTATATE included sensitivity, specificity, negative predictive value, positive predictive value, and accuracy. Inter- and intra-reader reliability, as well as ability to differentiate between localized and metastatic disease, was also determined. Adverse events (AEs) were recorded from 64Cu-DOTATATE injection through 48 hours post-injection. Results: The dose-ranging study identified 148 MBq (4.0 mCi) as the optimal dose to obtain diagnostic quality PET/CT images. Following database lock, diagnostic performance from an initial majority read of the 3 independent readers showed a significant 90.9% sensitivity (P = 0.0042) and 96.6% specificity (P < 0.0001) for detecting NETs, which translated to a 100.0% sensitivity and 96.8% specificity after correcting for an initial SOT misread. Excellent inter- and intra-reader reliability, as well as ability to distinguish between localized and metastatic disease, was also noted. No AEs were related to 64Cu-DOTATATE, and no serious AEs were observed. Conclusion: 64Cu-DOTATATE PET/CT is a safe imaging technique that provides high-quality and accurate images at a dose of 148 MBq (4.0 mCi) for the detection of somatostatin-expressing NETs. Full Article
