Guardians of precision: advancing radiation protection, safety, and quality systems in nuclear medicine

BACKGROUND

In the rapidly evolving field of nuclear medicine, the paramount importance of radiation protection, safety, and quality systems cannot be overstated. This document provides a comprehensive analysis of the intricate regulatory frameworks and guidelines, meticulously crafted and updated by national and international regulatory bodies to ensure the utmost safety and efficiency in the practice of nuclear medicine.

METHODS

We explore the dynamic nature of these regulations, emphasizing their adaptability in accommodating technological advancements and the integration of nuclear medicine with other medical and scientific disciplines.

RESULTS

Audits, both internal and external, are spotlighted for their pivotal role in assessing and ensuring compliance with established standards, promoting a culture of continuous improvement and excellence. We delve into the significant contributions of entities like the International Atomic Energy Agency (IAEA) and relevant professional societies in offering universally applicable guidelines that amalgamate the latest in scientific research, ethical considerations, and practical applicability.

CONCLUSIONS

The document underscores the essence of international collaborations in pooling expertise, resources, and insights, fostering a global community of practice where knowledge and innovations are shared. Readers will gain an in-depth understanding of the practical applications, challenges, and opportunities presented by these regulatory frameworks and audit processes. The ultimate goal is to inspire and inform ongoing efforts to enhance safety, quality, and effectiveness in nuclear medicine globally.

Six country vignettes: Strengthening radiotherapy and theranostics

BACKGROUND

For cancer patient populations worldwide, the synchronous scale-up of diagnostics and treatments yields meaningful gains in survival and quality of life. Among advanced cancer therapies, radiotherapy (RT) and theranostics are key to achieving practical, high-quality, and personalized precision medicine - targeting disease manifestations of individual patients and broad populations, alike. Aiming to learn from one another across different world regions, the six country vignettes presented here depict both challenges and victories in de novo establishment or improvement of RT and theranostics infrastructure.

METHODS

The International Atomic Energy Agency (IAEA) convened global RT and theranostics experts from diverse world regions and contexts to identify relevant challenges and report progress in their own six countries: Belgium, Brazil, Costa Rica, Jordan, Mongolia, and South Africa. These accounts are collated, compared, and contrasted herein.

RESULTS

Common challenges persist which could be more strategically assessed and addressed. A quantifiable discrepancy entails personnel. The estimated radiation oncologists (ROs), nuclear medicine physicians (NMPs), and medical physicists (MPs for RT and nuclear medicine) per million inhabitants in the six collective countries respectively range between 2.69-38.00 ROs, 1.00-26.00 NMPs, and 0.30-3.45 MPs (Table 1), reflecting country-to-country inequities which largely match World Bank country-income stratifications.

CONCLUSION

Established goals for RT and nuclear medicine advancement worldwide have proven elusive. The pace of progress could be hastened by enhanced approaches such as more sustainably phased implementation; better multinational networking to share lessons learned; routine quality and safety audits; as well as capacity building employing innovative, resource-sparing, cutting-edge technologic approaches. Bodies such as ministries of health, professional societies, and the IAEA shall serve critical roles in convening and coordinating more innovative RT and theranostics translational research, including expanding nuanced global database metrics to inform, reach, and potentiate milestones most meaningfully.

POLICY SUMMARY

Aligned with WHO 25×25 NCDs target; WHA70.12 and WHA76.5 resolutions.

Mapping of Radiation Oncology and Gynecologic Oncology Services Available to Treat the Growing Burden of Cervical Cancer in Africa

PURPOSE

To meet the demand for cervical cancer care in Africa, access to surgical and radiation therapy services needs to be understood. We thus mapped the availability of gynecologic and radiation therapy equipment and staffing for treating cervical cancer.

METHODS AND MATERIALS

We collected data on gynecologic and radiation oncology staffing, equipment, and infrastructure capacities across Africa. Data was obtained from February to July 2021 through collaboration with international partners using Research Electronic Data Capture. Cancer incidence was taken from the International Agency for Research on Cancer's GLOBOCAN 2020 database. Treatment capacity, including the numbers of radiation oncologists, radiation therapists, physicists, gynecologic oncologists, and hospitals performing gynecologic surgeries, was calculated per 1000 cervical cancer cases. Adequate capacity was defined as 2 radiation oncologists and 2 gynecologic oncologists per 1000 cervical cancer cases.

RESULTS

Forty-three of 54 African countries (79.6%) responded, and data were not reported for 11 countries (20.4%). Respondents from 31 countries (57.4%) reported access to specialist gynecologic oncology services, but staffing was adequate in only 11 countries (20.4%). Six countries (11%) reported that generalist obstetrician-gynecologists perform radical hysterectomies. Radiation oncologist access was available in 39 countries (72.2%), but staffing was adequate in only 16 countries (29.6%). Six countries (11%) had adequate staffing for both gynecologic and radiation oncology; 7 countries (13%) had no radiation or gynecologic oncologists. Access to external beam radiation therapy was available in 31 countries (57.4%), and access to brachytherapy was available in 25 countries (46.3%). The number of countries with training programs in gynecologic oncology, radiation oncology, medical physics, and radiation therapy were 14 (26%), 16 (30%), 11 (20%), and 17 (31%), respectively.

CONCLUSIONS

We identified areas needing comprehensive cervical cancer care infrastructure, human resources, and training programs. There are major gaps in access to radiation oncologists and trained gynecologic oncologists in Africa.

The American Brachytherapy Society and Indian Brachytherapy Society consensus statement for the establishment of high-dose-rate brachytherapy programs for gynecological malignancies in low- and middle-income countries

PURPOSE

The global cervical cancer burden is disproportionately high in low- and middle-income countries (LMICs), and outcomes can be governed by the accessibility of appropriate screening and treatment. High-dose-rate (HDR) brachytherapy plays a central role in cervical cancer treatment, improving local control and overall survival. The American Brachytherapy Society (ABS) and Indian Brachytherapy Society (IBS) collaborated to provide this succinct consensus statement guiding the establishment of brachytherapy programs for gynecological malignancies in resource-limited settings.

METHODS AND MATERIALS

ABS and IBS members with expertise in brachytherapy formulated this consensus statement based on their collective clinical experience in LMICs with varying levels of resources.

RESULTS

The ABS and IBS strongly encourage the establishment of HDR brachytherapy programs for the treatment of gynecological malignancies. With the consideration of resource variability in LMICs, we present 15 minimum component requirements for the establishment of such programs. Guidance on these components, including discussion of what is considered to be essential and what is considered to be optimal, is provided.

CONCLUSIONS

This ABS/IBS consensus statement can guide the successful and safe establishment of HDR brachytherapy programs for gynecological malignancies in LMICs with varying levels of resources.

Radiotherapy Capabilities, Population, Average Income, and Health Insurance Status as Predictors of Cancer Mortality at the County Level in the United States

PURPOSE/OBJECTIVE(S)

Sufficient radiotherapy capacity at the country level is commonly seen in high income countries and is an essential factor in access to high quality cancer care. However, universal access is not always possible due to other factors beyond the commonly used parameter of machines per million population. This study aims to assess the barriers cancer patients in a high-income country face in accessing radiotherapy, and how this impacts cancer mortality.

MATERIALS/METHODS

This cross-sectional study utilized United States county level oncologic and demographic data obtained from Centers for Disease Control and Prevention and the International Atomic Energy Agency Directory of Radiotherapy Centers. Radiotherapy facilities in the United States were mapped using Geographic Information Systems software. Univariate analysis was used to identify whether distance to a radiotherapy center or various socioeconomic factors were predictive of all-cancer mortality-to-incidence ratios. Variables that were deemed to be significant (p ≤ 0.05) on univariate analysis were then included in a step-wise backwards elimination method of multiple regression analysis.

RESULTS

Among the United States counties studied, 31.3% of counties have at least one radiotherapy facility and 8.3% have five or more radiotherapy facilities. Median linear distance from a county's centroid to the nearest radiotherapy center was 36 Km and the median county all-cancer mortality to incidence ratio (MIR) was 0.37. The ratio of radiotherapy centers, linear accelerators and brachy therapy units per 1 million people were significantly associated with all-cancer MIR (p<0.05). Greater distance to radiotherapy facilities, lower county population, lower average income per county, and higher proportion of patients without health insurance were statistically significant predictors of increased all-cancer MIR (R-squared: 0.2113, F = 94.22, p<0.001).

CONCLUSION

This analysis used unique high-quality datasets to identify significant barriers to radiotherapy access that correspond to higher cancer mortality at the county level. Geographic access, personal income, and insurance status all contribute to these concerning disparities. Efforts and novel strategies to address and minimize these barriers are needed to ensure access to care and improve oncologic outcomes.

Radiotherapy Resources in Latin America and the Caribbean: An International Atomic Energy Agency Analysis of Current and Projected Needs

PURPOSE/OBJECTIVE(S)

The inequitable access to radiotherapy (RT) is recognized to be a complex undertaking that will require sustained work identifying gaps and mobilizing efforts to fill in those gaps. Data can support policy-makers as they embark on programs to reduce premature mortality from cancer in their countries and regions. The purpose of this analysis is to identify the current gaps and needs in Latin America and the Caribbean (LAC).

MATERIALS/METHODS

We created a database of 41 countries in LAC using open-source data, including data on population size (UN Department of Economic and Social Affairs data), gross national income per capita (GNIPC) (World Bank Data), current and projected cancer incidence and mortality (Globocan 2020). The International Atomic Energy Agency (IAEA) Directory of Radiotherapy Centers (DIRAC) was used to identify the number and operational status of megavoltage (MV) teletherapy machines (Cobalt-60 and Linear Accelerators LINACs) and brachytherapy facilities (HDR and LDR). To calculate current and projected gaps in external beam RT (EBRT) facilities, we matched DIRAC data with Globocan cancer incidence data for 2020 and projections for 2025 and 2030 while applying a 64% optimal EBRT utilization rate (taking into account re-treatment). For brachytherapy, analysis took into account both HDR and LDR capacity and was primarily focused on needs based on current and projected incidence of cervical cancer cases in LAC.

RESULTS

EBRT was available in 32 (76%) of 41 countries. There were 742 RT centers in 32 countries with a total of 1131 MV units. Average coverage in 2022 based on an optimal utilization rate of 64% was 64%. LINACs accounted for 87% of the total MV units and Cobalt-60 capacity decreased to 13% of total teletherapy capacity compared to capacity in 2018. Most countries clustered in the same range of GNIPC to teletherapy units per 1000 cases, however outliers were most notable in the Caribbean. The median GNIPC was $6340 and the median MV units per 1000 cancer cases were 1.4. The current deficit in MV units is estimated at 672 megavoltage units and projected to be 2455 units by 2030 representing more than double the current capacity. 28 out of 41 countries (68%) had brachytherapy including 279 installed services, both HDR and LDR. At a 75% optimal utilization rate of brachytherapy in locally advanced cervical cancer, the current brachytherapy capacity in LAC could treat 108,420 patients with cervical cancer/year, which meets the current needs in the region albeit with significant inequity in distribution of resources.

CONCLUSION

There is 15% improvement in the current EBRT capacity in LAC compared to 2018. However, there is still shortage of at least 672 extra units needed. By 2030, the need for MV units will be double the current capacity. The current brachytherapy capacity meets needs albeit with inequitable distribution across the region primarily in the Caribbean.

Radiotherapy resources in Latin America and the Caribbean: a review of current and projected needs based on International Atomic Energy Agency data

The inequitable access to radiotherapy globally is a complex undertaking that will require sustained work identifying gaps and mobilising efforts to resolve. The purpose of this review is to identify gaps and needs in radiotherapy in Latin America and the Caribbean. Data from 41 countries in Latin America and the Caribbean on teletherapy megavoltage units and brachytherapy resources were extracted from the International Atomic Energy Agency (IAEA) Directory of Radiotherapy Centers. These data were then matched to open-source data from GLOBOCAN and World Bank Data which included data on population size, gross national income per capita, cancer incidence, and mortality. These data were matched to current and projected cancer incidence and mortality (as estimated by the Global Cancer Observatory in 2020) to calculate current and projected gaps in external beam radiotherapy facilities. For brachytherapy, the analysis was focused on cervical cancer and included high dose rate and low dose rate machines. As of Oct 22, 2022, external beam radiotherapy was available in 32 (78%) of 41 countries, representing 742 radiotherapy centres and 1122 megavoltage units. Average coverage was 63%. LINACs accounted for 85% (955 of 1122) of megavoltage units and Cobalt-60 capacity decreased to 12% compared with in 2018. Median megavoltage units per 1000 cancer cases were 0·8 (IQR 0·54-1·03). Most countries clustered in the same range of gross national income per capita for teletherapy units per 1000 cases at a median of US$9380. The current deficit in megavoltage units is estimated at 668 units and is projected to be 2455 units by 2030. 28 (68%) of 41 countries had 279 installed brachytherapy services, both high dose rate and low dose rate, which could treat 108 420 patients with cervical cancer per year and meet the current needs, albeit with inequitable distribution of resources. Overall, this review indicated a 15% improvement in the current external beam radiotherapy capacity in Latin America and the Caribbean compared with 2018. However, there is still a current shortage of at least 668 extra units. By 2030, the need for megavoltage units will be double the current capacity. There is inequitable distribution of brachytherapy resources across the region primarily in the Caribbean. Adoption of hypofractionation can help overcome machine shortage; however, it will present technical challenges that need to be taken into account. Rays of Hope, is a novel IAEA initiative that is designed to mobilise global efforts to address radiotherapy gaps while ensuring the highest return on investment.

Proximity to Radiotherapy Center, Population, Average Income, and Health Insurance Status as Predictors of Cancer Mortality at the County Level in the United States

PURPOSE

Sufficient radiotherapy (RT) capacity is essential to delivery of high-quality cancer care. However, despite sufficient capacity, universal access is not always possible in high-income countries because of factors beyond the commonly used parameter of machines per million people. This study assesses the barriers to RT in a high-income country and how these affect cancer mortality.

METHODS

This cross-sectional study used US county-level data obtained from Center for Disease Control and Prevention and the International Atomic Energy Agency Directory of Radiotherapy Centres. RT facilities in the United States were mapped using Geographic Information Systems software. Univariate analysis was used to identify whether distance to a RT center or various socioeconomic factors were predictive of all-cancer mortality-to-incidence ratio (MIR). Significant variables (P ≤ .05) on univariate analysis were included in a step-wise backward elimination method of multiple regression analysis.

RESULTS

Thirty-one percent of US counties have at least one RT facility and 8.3% have five or more. The median linear distance from a county's centroid to the nearest RT center was 36 km, and the median county all-cancer MIR was 0.37. The amount of RT centers, linear accelerators, and brachytherapy units per 1 million people were associated with all-cancer MIR (P < .05). Greater distance to RT facilities, lower county population, lower average income per county, and higher proportion of patients without health insurance were associated with increased all-cancer MIR (R-squared, 0.2113; F, 94.22; P < .001).

CONCLUSION

This analysis used unique high-quality data sets to identify significant barriers to RT access that correspond to higher cancer mortality at the county level. Geographic access, personal income, and insurance status all contribute to these concerning disparities. Efforts to address these barriers are needed.

Equity in adjuvant radiotherapy utilization in locally advanced head and neck cancer: A SEER-data based study

BACKGROUND

Not all patients with locally advanced head and neck cancer (HNC) who are eligible for adjuvant radiotherapy (RT) following upfront surgery appear to receive it.

METHODS

Data were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Selected patients from 2009 to 2018 had locally advanced HNC, underwent upfront surgery, and were eligible for adjuvant RT. Multivariable logistic regression and chi-squared test were used to analyze available patient and tumor characteristics.

RESULTS

Of 12 549 patients, 84.5% underwent adjuvant RT, 15.5% did not. Characteristics associated with lowest adjuvant RT utilization included cancers of the larynx (p < 0.0001) and gingivae (p < 0.0001), age 80 and above (p < 0.0001), unpartnered status (p < 0.0001), and residence within a nonmetropolitan area (p < 0.0024).

CONCLUSIONS

Tumor subsite, age, partnered status, and rural/urban residence correlate with omission of adjuvant RT in locally advanced HNC.

Current update of treatment strategies for borderline resectable pancreatic cancer: a narrative review

Background and Objective

Borderline resectable pancreatic cancer (BRPC) is a tumor that infiltrates into the large blood vessels, with a high probability that the tumor will remain after surgical resection. To date, there has been no confirmed treatment strategy for BRPC. However, high-level studies, such as those using the intention-to-treat analysis, have recently been published. This review aimed to update the current status of treatment strategies for BRPC.

Methods

We searched for studies, including those investigating patients with BRPC, either treated by upfront surgery or with neoadjuvant treatment and reported the R0 resection rate and overall survival using an intention-to-treat analysis.

Key Content and Findings

Consequently, 22 articles were identified. Twelve were prospective studies. Six studies compared neoadjuvant therapy with upfront surgery, and both the R0 resection rate and overall survival in patients who underwent upfront surgery were significantly worse than in those who underwent neoadjuvant treatment in all studies. Six studies evaluated neoadjuvant chemotherapy, while 15 studies neoadjuvant chemoradiation. No reports showed the superiority or inferiority of the two methods, and the optimal regimen was not determined in either treatment. The high-precision radiation therapy techniques have been studied, but the optimal method and dose fractionation were unclear.

Conclusions

The current standard of care for the BRPC is neoadjuvant therapy. Although the optimal regimen of neoadjuvant therapy was not determined, several prospective trials are underway to identify the optimal neoadjuvant treatment.

Point-A vs. volume-based brachytherapy for the treatment of cervix cancer: A meta-analysis

BACKGROUND & PURPOSE

To report disease-free survival (DFS) for volume-based and point-A based brachytherapy (BT) in locally advanced cervical cancer.

MATERIALS & METHODS

We conducted a meta-analysis of studies assessing the effects of point-A and volume-based brachytherapy on 3-year DFS. Studies including stage I-IVA cervical cancer patients were included if standard treatment of concomitant chemo-radiotherapy and high-dose- or pulsed dose rate BT was delivered. The primary outcome was 3-year DFS, and secondary outcomes were 3-year local control (LC), 3-year overall survival (OS) and late toxicity. A random-effects subgroup meta-analysis was done.

RESULTS

In total, 5499 studies were screened, of which 24 studies with 5488 patients were eligible. There was significant heterogeneity among point-A studies (1538 patients) (I² = 82%, p < 0.05) relative to volume-based studies (3950 patients) (I² = 58, p = 0.01). The 3-year DFS for point-A and volume-based studies were 67% (95% CI 60%-73%) and 79% (95% CI 76%-82%) respectively (p = 0.001). Three-year LC for point-A and volume-based studies were 86% (95% CI 81%-90%) and 92% (91%-94%) respectively (p = 0.01). The difference in 3-year OS (72% vs. 79%, p = 0.12) was not statistically significant. The proportion of prospectively enrolled patients was 23% for point-A studies and 33% for volume-based studies. There was no difference in late grade 3 or higher gastrointestinal (3% vs. 4%, p = 0.76) genitourinary toxicities (3% vs. 3% p = 0.45) between the two groups.

CONCLUSION

Volume-based BT results in superior 3-year DFS and 3-year LC. In the absence of randomized trials, this meta-analysis provides the best evidence regarding transition to 3D planning.

Prognostic significance of left atrial reservoir strain in patients undergoing transcatheter aortic valve implantation

Funding Acknowledgements

Type of funding sources: None.

Background

Left atrial reservoir strain (LARS) provides prognostic information in various patient groups and might help to detect elevated filling pressures. Patients with diastolic dysfunction experience worse outcomes after transcatheter aortic valve implantation (TAVI), but Doppler-derived measurements might be hampered by atrial fibrillation, mitral valve disease or impaired image quality. Aim of the current study is to elucidate the prognostic value of LASR in patients undergoing TAVI.

Methods

 All consecutive patients undergoing TAVI at a single tertiary care hospital between 01/2018 and 12/2018 were included if discharge echo and follow-up was available. LASR was derived from 2-D-speckle-tracking averaged apical 2- and 4-chamber view. Patients were grouped in 3 tertiles according to LASR. Primary outcome was a composite of all-cause death and readmission for worsening heart failure.

Results

Overall, 606 patients were available (Age 80 years (IQR 77-84)), including 53% woman. 

LASR was significantly impaired over tertiles (T1 21.4  (IQR 18.3-24.5), T2 13.0  (IQR 11.3-14.6), T3 7.1  (IQR 5.4-8.4), p &lt; 0.0001). The primary outcome occurred more often with impaired LASR (T1 7,4%, T2 13.4%, T3 25,7%). 

 On multivariable Cox-regression analysis LASR was a significant factor to predict outcome (HR 0.95, CI 0.91-0.99, p = 0.02).

Conclusion

Impaired LASR is associated with impaired outcomes in patients undergoing TAVI.

Radiotherapy resources in Africa: an International Atomic Energy Agency update and analysis of projected needs

The number of patients with cancer in Africa has been predicted to increase from 844 279 in 2012 to more than 1·5 million in 2030. However, many countries in Africa still lack access to radiotherapy as a part of comprehensive cancer care. The objective of this analysis is to present an updated overview of radiotherapy resources in Africa and to analyse the gaps and needs of the continent for 2030 in the context of the UN Sustainable Development Goals. Data from 54 African countries on teletherapy megavoltage units and brachytherapy afterloaders were extracted from the Directory for Radiotherapy Centres, an electronic, centralised, and continuously updated database of radiotherapy centres. Cancer incidence and future predictions were taken from the GLOBOCAN 2018 database of the International Agency for Research on Cancer. Radiotherapy need was estimated using a 64% radiotherapy utilisation rate, while assuming a machine throughput of 500 patients per year. As of March, 2020, 28 (52%) of 54 countries had access to external beam radiotherapy, 21 (39%) had brachytherapy capacity, and no country had a capacity that matched the estimated treatment need. Median income was an important predictor of the availability of megavoltage machines: US$1883 (IQR 914-3269) in countries without any machines versus $4485 (3079-12480) in countries with at least one megavoltage machine (p=0·0003). If radiotherapy expansion continues at the rate observed over the past 7 years, it is unlikely that the continent will meet its radiotherapy needs. This access gap might impact the ability to achieve the Sustainable Development Goals, particularly the target to reduce preventable, premature mortality by a third, and meet the target of the cervical cancer elimination strategy of 90% with access to treatment. Urgent, novel initiatives in financing and human capacity building are needed to change the trajectory and provide comprehensive cancer care to patients in Africa in the next decade.

Global Radiotherapy: Current Status and Future Directions-White Paper

Recognizing the increase in cancer incidence globally and the need for effective cancer control interventions, several organizations, professional bodies, and international institutions have proposed strategies to improve treatment options and reduce mortality along with minimizing overall incidence. Despite these efforts, an estimated 9.6 million deaths in 2018 was attributed to this noncommunicable disease, making it the second leading cause of death worldwide. Left unchecked, this will further increase in scale, with an estimated 29.5 million new cases and 16.3 million deaths occurring worldwide in 2040. Although it is known and generally accepted that cancer services must include radiotherapy, such access is still very limited in many parts of the world, especially in low- and middle-income countries. After thorough review of the current status of radiotherapy including programs worldwide, as well as achievements and challenges at the global level, the International Atomic Energy Agency convened an international group of experts representing various radiation oncology societies to take a closer look into the current status of radiotherapy and provide a road map for future directions in this field. It was concluded that the plethora of global and regional initiatives would benefit further from the existence of a central framework, including an easily accessible repository through which better coordination can be done. Supporting this framework, a practical inventory of competencies needs to be made available on a global level emphasizing the knowledge, skills, and behavior required for a safe, sustainable, and professional practice for various settings. This white paper presents the current status of global radiotherapy and future directions for the community. It forms the basis for an action plan to be developed with professional societies worldwide.

Pre-procedural high-pitch coronary CT angiography assessment of patients undergoing transcatheter aortic valve implantation (TAVI) without patient-specific adjustment: analysis of diagnostic performance

AIM

To evaluate the ability to assess the coronary arteries using pre-procedural computed tomography (CT; high-pitch mode) in patients referred for transcatheter aortic valve implantation (TAVI).

METHODS AND MATERIALS

CT and invasive coronary angiography (ICA) were performed pre-TAVI in 100 patients (46 women; 79 ± 5.9 years). CT was performed in prospectively ECG-triggered high-pitch mode after intravenous administration of 70 ml iodinated contrast medium. Image quality was assessed using a four-point scale (graded 0-3). Significant coronary artery stenosis (≥50% diameter) was graded as either present or absent by one observer and in one-third of patients by two observers independently. ICA was the standard of reference. Results were reported per segment and per patient.

RESULTS

Twenty-two percent of patients had known coronary artery disease (CAD). In two cases, a coronary anomaly was detected. Diagnostic image quality (grade 1-3) was achieved in 30.3% of segments. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 75%, 80.5%, 16%, and 98.5%, respectively. Significant coronary stenosis could be ruled out completely in all segments in three patients. The interrater agreement per patient was excellent (kappa = 1).

CONCLUSION

Relevant coronary findings can frequently be observed in high-pitch TAVI-planning CT. Despite the limitations of the technique and in patients referred to pre-TAVI evaluation (rapid heart rate, coronary calcifications, etc.), a valid evaluation of coronary arteries is possible in a considerable proportion of segments with a high NPV; however, few studies were completely free of motion artefacts to dependably exclude CAD using this technique in this challenging group of patients.

Shift in parasitic infections during the Corona pandemic: a hospital-based retrospective study

The Corona pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) calls on the Saudi government to take action to control the infection. The government closed borders, prohibited travel, limited outdoor movements, and told primary and secondary care facilities to reduce all regular non-urgent health services. It is not known whether these measures have impacted the prevalence of parasitic intestinal infections. This study has therefore been carried out to investigate this issue. Dataset of 217 stool samples submitted to the King Faisal Medical Complex (KFMC) Microbiology Laboratory in Taif, Saudi Arabia for parasitological examination during the pandemic (January-June 2020) and 649 samples submitted during the corresponding months of the previous year (January-June 2019) were extracted and analyzed. Overall, 24.1% (209/866) of samples were parasitespositives; 26.6% (173/649) before and 16.5% (36/217) during the pandemic, with 79% reduction. There was a significant difference in gender-parasitism between the two periods where the majority of parasitism were for males (p<0.001). Infections were frequent in patients aged 5- 14 years both before (84/649; 12.9%) and during (12/217; 5.5%) the pandemic, with significant difference observed between the two cohorts (p<0.002). Moreover, the majority of infected patients were non-Saudi (67.9%; 142/209), with a significant difference in nationality reported, (p=0.024). Protozoa were identified in 21.8% (189) of all samples investigated, of which, Blastocystis hominis, Entamoeba coli, Giardia lamblia, Entamoeba histolytica/dispar and Cryptosporidium species were identified in 6.1% (53), 5.4% (47), 5.0% (44), 2.8% (25), and 2.3% (20), respectively. Helminths were diagnosed in 2.3% (20/866) of samples. Eggs of hookworm, Ascaris, Taenia spp, and Hymenolepis nana were detected in 0.9% (8), 0.5% (5), 0.3% (3) and 0.4% (4), respectively. In parallel with our research hypothesis, a substantial decrease in the burden of intestinal parasitic infections was recorded with the lock-down measures taken during the Corona pandemic.

The timing and design of stereotactic radiotherapy approaches as a part of neoadjuvant therapy in pancreatic cancer: Is it time for change?

Stereotactic Radiotherapy (SRT) over 5-15 days can be interdigitated without delaying chemotherapy. Bridging chemotherapy may allow for extended intervals to surgery, potentially improving sterilization of surgical margins and overall survival. SRT for pancreatic adenocarcinoma should not be limited to the tumor, and should consider hypofractionated approaches to regional nodes.

Medical imaging and nuclear medicine: a Lancet Oncology Commission

The diagnosis and treatment of patients with cancer requires access to imaging to ensure accurate management decisions and optimal outcomes. Our global assessment of imaging and nuclear medicine resources identified substantial shortages in equipment and workforce, particularly in low-income and middle-income countries (LMICs). A microsimulation model of 11 cancers showed that the scale-up of imaging would avert 3·2% (2·46 million) of all 76·0 million deaths caused by the modelled cancers worldwide between 2020 and 2030, saving 54·92 million life-years. A comprehensive scale-up of imaging, treatment, and care quality would avert 9·55 million (12·5%) of all cancer deaths caused by the modelled cancers worldwide, saving 232·30 million life-years. Scale-up of imaging would cost US$6·84 billion in 2020-30 but yield lifetime productivity gains of $1·23 trillion worldwide, a net return of $179·19 per $1 invested. Combining the scale-up of imaging, treatment, and quality of care would provide a net benefit of $2·66 trillion and a net return of $12·43 per $1 invested. With the use of a conservative approach regarding human capital, the scale-up of imaging alone would provide a net benefit of $209·46 billion and net return of $31·61 per $1 invested. With comprehensive scale-up, the worldwide net benefit using the human capital approach is $340·42 billion and the return per dollar invested is $2·46. These improved health and economic outcomes hold true across all geographical regions. We propose actions and investments that would enhance access to imaging equipment, workforce capacity, digital technology, radiopharmaceuticals, and research and training programmes in LMICs, to produce massive health and economic benefits and reduce the burden of cancer globally.

IAEA consultancy meeting on low-dose radiation for patients and population

This paper reports on the IAEA's Consultancy Meeting on "low-dose radiation for patients and population -Science, Technology and Society (STS) concepts for communication and perception among medical doctors and stakeholders-", which was held on October 21 and 22, 2020. The meeting consisted of seven presentation sessions, with a total of 27 presentations and 39 participants from seven countries. The meeting focused on various areas including environmental, food, and personal dosimetry;radiation and other secondary health effects after nuclear disasters;communication between medical professionals and patients or residents;and medical education on nuclear accidents. This meeting was convened to discuss STS perspectives related to nuclear emergencies, to share the findings of the Fukushima Health Management Survey and the current situation in Fukushima with international experts. The meeting confirmed the importance of coordinated recovery of affected areas and global preparedness in the aftermath of nuclear accidents.

Multivessel versus culprit-only PCI in STEMI patients with multivessel disease: meta-analysis of randomized controlled trials

Background

Previous randomized controlled trials (RCTs) indicated a benefit of multivessel percutaneous coronary intervention (PCI) compared to culprit vessel-only PCI in ST-elevation myocardial infarction (STEMI) without cardiogenic shock.

Purpose

To perform a pairwise meta-analysis of RCTs, already including the recently published COMPLETE (The Complete versus Culprit-Only Revascularization Strategies to Treat Multivessel Disease after Early PCI for STEMI) trial, comparing multivessel PCI and culprit vessel-only PCI in STEMI patients without cardiogenic shock.

Methods

We searched MEDLINE, Cochrane Central Register of Controlled Trials, and Embase for randomized controlled trials (RCTs) comparing multivessel PCI with culprit vessel-only PCI in STEMI patients without cardiogenic shock and multivessel coronary artery disease. Only RCTs reporting mortality or myocardial reinfarction after at least 6 months following randomization were included. Hazard ratios (HRs) were pooled using random-effect models.

Results

Nine RCTs were included in the final analysis. In total, 523 (8.3%) of 6,314 patients suffered the combined primary endpoint of death or non-fatal reinfarction. This primary endpoint was significantly reduced with multivessel PCI compared to culprit vessel-only PCI (HR 0.63, 95% confidence interval [CI] 0.43–0.93; p=0.03). This finding was driven by a reduction of non-fatal reinfarction (HR 0.64, 95% CI 0.52–0.79; p=0.001), whereas no significant reduction of all-cause death (HR 0.77, 95% CI 0.44–1.35; p=0.28) or cardiovascular death (HR 0.64, 95% CI 0.37–1.11; p=0.09) was observed.

Conclusion

In STEMI patients without cardiogenic shock multivessel PCI reduced the risk of death or non-fatal reinfarction compared to culprit vessel-only PCI.

Funding Acknowledgement

Type of funding source: None

Addressing Global Inequities in Positron Emission Tomography-Computed Tomography (PET-CT) for Cancer Management: A Statistical Model to Guide Strategic Planning

Background

According to the World Health Organization (WHO), non-communicable diseases are responsible for 71% of annual global mortality. National governments and international organizations are increasingly considering medical imaging and nuclear medicine access data in strategies to address epidemiologic priorities. Our objective here was to develop a statistical model to assist countries in estimating their needs for PET-CT systems for the management of specific cancer types.

Material/Methods

We introduce a patient-centered statistical model based on country-specific epidemiological data, PET-CT performance, and evidence-based clinical guidelines for PET-CT use for cancer. The output of the model was integrated into a Bayesian model to rank countries or world regions that would benefit the most from upscaling PET-CT scanners.

Results

We applied our model to the IMAGINE database, recently developed by the International Atomic Energy Agency (IAEA). Our model indicates that at least 96 countries should upscale their PET-CT services and more than 200 additional PET-CT scanners would be required to fulfill their needs. The model also provides quantitative evidence indicating that low-income countries would benefit the most from increasing PET-CT provision. Finally, we discuss several cases in which the standard unit [number of scanners]/[million inhabitants] to guide strategic planning or address inequities is misleading.

Conclusions

Our model may help in the accurate delineation and further reduction of global inequities in access to PET-CT scanners. As a template, the model also has the potential to estimate the costs and socioeconomic impact of implementing any medical imaging modality for any clinical application.

Understanding High-Dose, Ultra-High Dose Rate, and Spatially Fractionated Radiation Therapy

The National Cancer Institute's Radiation Research Program, in collaboration with the Radiosurgery Society, hosted a workshop called Understanding High-Dose, Ultra-High Dose Rate and Spatially Fractionated Radiotherapy on August 20 and 21, 2018 to bring together experts in experimental and clinical experience in these and related fields. Critically, the overall aims were to understand the biological underpinning of these emerging techniques and the technical/physical parameters that must be further defined to drive clinical practice through innovative biologically based clinical trials.

Correction to: Nuclear medicine services after COVID-19: gearing up back to normality

The authors P. Orellana and N. El-Haj were inadvertently deleted in the original paper.

Executive Summary of the American Radium Society Appropriate Use Criteria for Local Excision in Rectal Cancer

The goal of treatment for early stage rectal cancer is to optimize oncologic outcome while minimizing effect of treatment on quality of life. The standard of care treatment for most early rectal cancers is radical surgery alone. Given the morbidity associated with radical surgery, local excision for early rectal cancers has been explored as an alternative approach associated with lower rates of morbidity. The American Radium Society Appropriate Use Criteria presented in this manuscript are evidence-based guidelines for the use of local excision in early stage rectal cancer that include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) used by a multidisciplinary expert panel to rate the appropriateness of imaging and treatment procedures. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. These guidelines are intended for the use of all practitioners and patients who desire information regarding the use of local excision in rectal cancer.

94Course of contained annulus ruptures after TAVI: the ENCORE (European contained rupture)-registry

Background

An asymptomatic contained rupture (CR) of the aortic annulus is a rare complication of transcatheter aortic valve implantation (TAVI). Their clinical implication is unclear so far.

Purpose

To determine the long-term outcomes in patients with CR.

Methods

The ENCORE-registry is a multicenter registry (6 centers across Europe) of patients with CR diagnosed on post-TAVI computed tomography angiography (CTA) or transesophageal echocardiography (TEE).

Results

A total of 21 patients (mean age 81.9±4.1 years, 81% balloon-expandable TAVI-prostheses) were diagnosed with CR (62% located adjacent to the left coronary cusp, mean size of lesions was 15.3±6.9 x 8.5±3.3 x 8.5±2.3 mm). Seventeen were diagnosed among a total of 1602 consecutive routine post-TAVI CTA (incidence 1.1%), two in TEE and two in post-TAVI CTA (each conducted due to suspicion of periinterventional complications). During a mean follow-up of 2.3±1.7 years nine patients (43%) died from non-cardiac causes. None of the patients exhibited symptoms or underwent interventional treatment related to the CR, no sudden cardiac death occurred. A follow-up CTA, performed in eleven patients 240±176 days post-TAVI, revealed stable CR findings in seven, regression in one, and remission in three patients.

Conclusion

The results of our ENCORE-registry demonstrate a benign course of initially asymptomatic contained ruptures of the aortic annulus after TAVI supporting a watch-and-wait approach in these patients. Thus, no specific treatment seems to be necessary.

P1251Percutaneous coronary intervention versus medical therapy for coronary lesions with positive fractional flow reserve (FFR) but preserved coronary flow reserve (CFR). A substudy of the COMPARE-ACUTE

Introduction

International guidelines recommend performing percutaneous coronary intervention (PCI) on stable coronary lesions with a positive fractional flow reserve (FFR) to improve clinical outcomes. It remains unclear if FFR positive lesions with preserved coronary flow reserved (CFR) might be better treated medically.

Purpose

This study compared clinical outcomes between PCI and medical therapy for stable FFR-positive lesions with preserved CFR.

Methods

We performed a substudy of the randomized, multicenter COMPARE-ACUTE trial in which treated ST-elevation myocardial infarction patients with stable non-culprit lesions were randomized to either FFR-guided PCI or medical therapy. Based on baseline and hyperaemic pressure gradients, we computed the so-called pressure bounded-CFR (pb-CFR) and classified lesions as low (<2) or preserved (≥2). Our primary end point was a composite of death from any cause, non-fatal myocardial infarction, revascularization, or cerebrovascular events (MACCE) at 12 months.

Results

A total of 980 lesions from 885 subjects were included in this sub-study due to availability of baseline and hyperaemic pressure gradients. For the 462 lesions with FFR≤0.80, 249 had a pb-CFR<2 while 29 had a preserved CFR (pb-CFR≥2). The rate of MACCE at 1 year did not differ significantly between subjects with FFR≤0.80 and pb-CFR<2 versus FFR≤0.80 and pb-CFR≥2 (24% vs. 30%, p=0.44). Because of randomization, baseline characteristics were well balanced between subjects with FFR≤0.80 and pb-CFR≥2 who were treated by PCI or medical therapy. Importantly for subjects with FFR≤0.80 and pb-CFR≥2, MACCE occurred more frequently when treated medically compared with PCI (50% vs. 0% respectively, p=0.01).

Conclusions

In this post-hoc substudy from a large randomized controlled trial of 885 subjects with 980 lesions, a preserved pb-CFR≥2 did not associate with an improved clinical outcome when FFR≤0.80. Subjects with FFR-positive coronary lesions but a preserved pb-CFR experienced significantly worse clinical outcomes when treated medically instead of with PCI. These data suggest that a stenosis with a FFR≤0.80, even when pb-CFR remains preserved, benefits from treatment with PCI.

Acknowledgement/Funding

Maasstad Cardiovascular Research, Abbott Vascular and St. Jude Medical