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.

Nanobiotechnology augmented cancer stem cell guided management of cancer: liquid-biopsy, imaging, and treatment

Cancer stem cells (CSCs) represent both a key driving force and therapeutic target of tumoral carcinogenesis, tumor evolution, progression, and recurrence. CSC-guided tumor diagnosis, treatment, and surveillance are strategically significant in improving cancer patients' overall survival. Due to the heterogeneity and plasticity of CSCs, high sensitivity, specificity, and outstanding targeting are demanded for CSC detection and targeting. Nanobiotechnologies, including biosensors, nano-probes, contrast enhancers, and drug delivery systems, share identical features required. Implementing these techniques may facilitate the overall performance of CSC detection and targeting. In this review, we focus on some of the most recent advances in how nanobiotechnologies leverage the characteristics of CSC to optimize cancer diagnosis and treatment in liquid biopsy, clinical imaging, and CSC-guided nano-treatment. Specifically, how nanobiotechnologies leverage the attributes of CSC to maximize the detection of circulating tumor DNA, circulating tumor cells, and exosomes, to improve positron emission computed tomography and magnetic resonance imaging, and to enhance the therapeutic effects of cytotoxic therapy, photodynamic therapy, immunotherapy therapy, and radioimmunotherapy are reviewed.

The potential role of artificial intelligence in sustainability of nuclear medicine

BACKGROUND

Strategies targeted at the five pillars of sustainability (social, human, economic, ecological and environmental) can be used to improve sustainability of clinical or research practices in nuclear medicine.

KEY FINDINGS

While the core principle of sustainability is ensuring depletion does not exceed regeneration, this manuscript considers the balance of benefits and detriments of artificial intelligence (AI) technologies across the five pillars of sustainability. Specifically, innovations such as AI, generative AI and digital twins could enhance sustainability. While AI has the potential to address social asymmetry and inequity to drive the social and human pillars of sustainability, there is potential for widening the equity gap. AI augmentation and generative AI present economic and environmental sustainability opportunities. Deep digital twins offers clinical and research benefits in economic, ecological and environmental sustainability pillars.

CONCLUSION

AI, digital twins and generative AI offer potential benefits to sustainability in nuclear medicine. Despite the benefits, caution is advised because these technologies confront a number of challenges that could potentially threaten sustainability.

IMPLICATIONS FOR PRACTICE

AI presents opportunities for improving sustainability of nuclear medicine practice although caution is recommended to avoid unintentional undermining of sustainability across the five pillars.

Preclinical development of novel PD-L1 tracers and first-in-human study of [68Ga]Ga-NOTA-RW102 in patients with lung cancers

BACKGROUND

The programmed cell death protein-1 (PD-1)/programmed death receptor ligand 1 (PD-L1) axis critically facilitates cancer cells' immune evasion. Antibody therapeutics targeting the PD-1/PD-L1 axis have shown remarkable efficacy in various tumors. Immuno-positron emission tomography (ImmunoPET) imaging of PD-L1 expression may help reshape solid tumors' immunotherapy landscape.

METHODS

By immunizing an alpaca with recombinant human PD-L1, three clones of the variable domain of the heavy chain of heavy-chain only antibody (VHH) were screened, and RW102 with high binding affinity was selected for further studies. ABDRW102, a VHH derivative, was further engineered by fusing RW102 with the albumin binder ABD035. Based on the two targeting vectors, four PD-L1-specific tracers ([68Ga]Ga-NOTA-RW102, [68Ga]Ga-NOTA-ABDRW102, [64Cu]Cu-NOTA-ABDRW102, and [89Zr]Zr-DFO-ABDRW102) with different circulation times were developed. The diagnostic efficacies were thoroughly evaluated in preclinical solid tumor models, followed by a first-in-human translational investigation of [68Ga]Ga-NOTA-RW102 in patients with non-small cell lung cancer (NSCLC).

RESULTS

While RW102 has a high binding affinity to PD-L1 with an excellent KD value of 15.29 pM, ABDRW102 simultaneously binds to human PD-L1 and human serum albumin with an excellent KD value of 3.71 pM and 3.38 pM, respectively. Radiotracers derived from RW102 and ABDRW102 have different in vivo circulation times. In preclinical studies, [68Ga]Ga-NOTA-RW102 immunoPET imaging allowed same-day annotation of differential PD-L1 expression with specificity, while [64Cu]Cu-NOTA-ABDRW102 and [89Zr]Zr-DFO-ABDRW102 enabled longitudinal visualization of PD-L1. More importantly, a pilot clinical trial shows the safety and diagnostic value of [68Ga]Ga-NOTA-RW102 immunoPET imaging in patients with NSCLCs and its potential to predict immune-related adverse effects following PD-L1-targeted immunotherapies.

CONCLUSIONS

We developed and validated a series of PD-L1-targeted tracers. Initial preclinical and clinical evidence indicates that immunoPET imaging with [68Ga]Ga-NOTA-RW102 holds promise in visualizing differential PD-L1 expression, selecting patients for PD-L1-targeted immunotherapies, and monitoring immune-related adverse effects in patients receiving PD-L1-targeted treatments.

TRIAL REGISTRATION NUMBER

NCT06165874.

The status of nuclear medicine in China: the first official national survey

AIM/INTRODUCTION

The National Nuclear Medicine Quality Control Center of China conducted the first official survey to investigate the nationwide situation of nuclear medicine in 2020. The survey aimed to unveil the current nuclear medicine situation and its quality control in China.

MATERIALS AND METHODS

The web-based survey was conducted and the data was collected via the National Clinical Improvement System (NCIS) of China from 1st April to 31st May 2021.

RESULTS

A total of 808 institutes across 30 provinces responded to the national survey. For human resources, there are 4460 physicians, 3077 technologists, 339 physicists, and 309 radiochemists. There are 887 single-photon imaging instruments, including 823 SPECT or SPECT/CT, and 365 PET instruments including 314 PET/CT. Six hundred twenty-four institutes perform SPECT examinations and 319 institutes perform PET examinations. 60% of SPECT scans are bone scintigraphy. A total of 97% of PET scans use an [18F]F-FDG tracer. Furthermore, 587 institutes provide radionuclide therapy services but only 280 institutes have admission rooms. The top three radionuclide therapies are [131I] therapy of hyperthyroidism with 546 institutes, [89Sr] therapy of bone metastasis with 400 institutes, and [131I] therapy of differentiated thyroid cancer with 286 institutes. Finally, for the frequency of equipment quality control per year, there are about 67 times self-test within the department for SPECT instruments and 111 times for PET instruments on average in each province. There are about three failures of SPECT and five failures of PET on average per year in each province. There are 408 institutes (of 624 SPECT institutes) performing quality control of SPECT radiopharmaceuticals, 216 (of 319) for PET radiopharmaceuticals, and 373 (of 587) for radionuclide therapy.

CONCLUSION

These results of the first official survey towards current status of nuclear medicine in China are the foundation for the establishment of the quality control management system.

EANM guidance document: dosimetry for first-in-human studies and early phase clinical trials

The numbers of diagnostic and therapeutic nuclear medicine agents under investigation are rapidly increasing. Both novel emitters and novel carrier molecules require careful selection of measurement procedures. This document provides guidance relevant to dosimetry for first-in human and early phase clinical trials of such novel agents. The guideline includes a short introduction to different emitters and carrier molecules, followed by recommendations on the methods for activity measurement, pharmacokinetic analyses, as well as absorbed dose calculations and uncertainty analyses. The optimal use of preclinical information and studies involving diagnostic analogues is discussed. Good practice reporting is emphasised, and relevant dosimetry parameters and method descriptions to be included are listed. Three examples of first-in-human dosimetry studies, both for diagnostic tracers and radionuclide therapies, are given.

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.

Utility of F-15 diuretic MAG3 renography in assessment of paediatric hydronephrosis

INTRODUCTION

Diuretic renography is crucial in evaluation of paediatric hydronephrosis. Furosemide is conventionally given 15-20 min after radiolabelled tracer (F+15/F+20 protocol), however this is equivocal in around 15% of patients. Giving furosemide 15 min prior to tracer (F-15 MAG3 protocol) has been suggested as an additional tool in the investigation of patients with suspected upper urinary tract obstruction. However, the role of this method in assessment and management of paediatric hydronephrosis is not widely reported.

OBJECTIVE

To investigate utility of F-15 renograms in children with hydronephrosis being assessed for Pelvi-Ureteric Junction Obstruction (PUJO).

STUDY DESIGN

Retrospective review of patients <16 years old undergoing F-15 MAG3 renogram between 2018 and 2021 in our tertiary paediatric surgical centre. Data collected included patient demographics, mode of presentation, investigations, management and outcomes.

RESULTS

Eighteen patients were included. Median age at F-15 renogram was 7.3 years. Eleven patients presented with antenatal hydronephrosis, 5 with symptoms in childhood and 2 with incidental hydronephrosis on trauma imaging. Fourteen patients were symptomatic. Ten had a prior non-obstructed F+20 renogram but persisting symptoms suggestive of PUJO. Seven had previous equivocal F+20 renograms. One symptomatic patient directly underwent an F-15 renogram. A conclusive result was obtained in 16/18 (89%); 11 patients had obstructed curves and 5 non-obstructed. Two asymptomatic patients' scans were inconclusive. All symptomatic patients had conclusive scans. Of 11 patients with an obstructed F-15, 9 have undergone pyeloplasty to date. All have had post-operative resolution in symptoms and static or improved post-operative ultrasound. One patient with an inconclusive scan underwent pyeloplasty due to persisting hydronephrosis and parent preference. Three patients with non-obstructed F-15 renograms have been discharged. One symptomatic patient with a non-obstructive F-15 had a ureteric stent inserted due to persistent flank pain; 1 continues under surveillance.

DISCUSSION

It is known that conventional F+20 MAG3 renograms can give equivocal results. Published experience suggests that F-15 renograms are conclusive in the majority of patients. Routine primary use is, however, discouraged as they can 'over diagnose' obstruction and limit the study of tracer transit under physiological flow rates. This study indicates that the F-15 renogram is a useful adjunct in the assessment of patients with symptoms suggestive of PUJO who have previously had an equivocal or a non-obstructed F+20 renogram.

CONCLUSION

F-15 renogram was conclusive in 89% of patients. We recommend using F-15 renograms to aid surgical decision-making in children with equivocal F+20 renograms, especially in the presence of symptoms.

Comparison of a 3D CZT and conventional SPECT/CT system for quantitative Lu-177 SPECT imaging

PURPOSE

Next-generation SPECT/CT systems with CdZnTe (CZT) digital detectors in a ring-like setup are emerging to perform quantitative Lu-177 SPECT imaging in clinical routine. It is essential to assess how the shorter acquisition time might affect the image quality and uncertainty on the mean absorbed dose of the tumors and organs at risk compared to a conventional system.

METHODS

A NEMA Image Quality phantom was scanned with a 3D CZT SPECT/CT system (Veriton, by Spectrum Dynamics) using 6 min per bed position and with a conventional SPECT/CT system (Symbia T16, by Siemens) using 16 min per bed position. The sphere-to-background ratio was 12:1 and the background activity concentration ranged from 0.52 to 0.06 MBq/mL. A clinical reconstruction protocol for dosimetry purposes was determined for both systems by maximizing the sphere-to-background ratio while keeping the coefficient of variation of the background as low as possible. The corresponding image resolution was determined by the matching filter method and used for a dose uncertainty assessment of both systems following an established uncertainty model..

RESULTS

The optimized iterative reconstruction protocol included scatter and attenuation correction for both systems and detector response modeling for the Siemens system. For the 3D CZT system, 6 iterations and 8 subsets were combined with a Gaussian post-filter of 3 mm Full Width Half Maximum (FWHM) for post-smoothing. For the conventional system, 16 iterations and 16 subsets were applied with a Gaussian post-smoothing filter of 1 mm FWHM. For these protocols, the sphere-to-background ratio was 18.5% closer to the true ratio for the conventional system compared to the 3D CZT system when considering the four largest spheres. Meanwhile, the background coefficient of variation was very similar for both systems. These protocols resulted in SPECT image resolution of 14.8 mm and 13.6 mm for the 3D CZT and conventional system respectively. Based on these resolution estimates, a 50% dose uncertainty corresponded to a lesion volume of 28 mL for the conventional system and a lesion volume of 33 mL for the 3D CZT system.

CONCLUSIONS

An optimized reconstruction protocol for a Veriton system with 6 min of acquisition time per bed position resulted in slightly higher dose uncertainties than a conventional Symbia system using 16 min of acquisition time per bed position. Therefore, a 3D CZT SPECT/CT allows to significantly reduce the acquisition times with only a very limited impact on dose uncertainties such that quantitative Lu-177 SPECT/CT imaging becomes much more accessible for treatment concurrent dosimetry. Nevertheless, the uncertainty of SPECT-based dose estimates remains high.

Optimal Indications of Radioimmunotherapy in Nuclear Medicine: A Mini-Review

Immunotherapy has emerged as a very considerable and potent therapeutic method in which immune inhibitors have gained a lot of attention in the curative field of various cancers. Under certain circumstances, when radiotherapy is accompanied by immunotherapy, the efficacy of the therapeutic procedure increases. Irradiated tumor cells follow a pathway called immunogenic cell death, which targets tumor associated antigens. The application of radiolabeled antibodies under the concept of "radioimmunotherapy" (RIT) makes the synergistic targeted therapeutic effect possible. Since antibodies themselves are cytotoxic, they can kill the cells that not only bind but are within the path length of their radiation emissions. RIT can be categorized as a substantial progress in nuclear medicine. The main concept of RIT includes targeting specified tumor-expressing antibodies. The mentioned purpose is achievable by formulation of radiolabeled antibodies, which could be injected intravenously or directly into the tumor, as well as compartmentally into a body cavity such as the peritoneum, pleura, or intrathecal space. RIT has demonstrated very optimistic therapeutic outcomes in radioresistant solid tumors. Wide ranges of efforts are accomplished in order to improve clinical trial accomplishments. In this review, we intend to summarize the performed studies on RIT and their importance in medicine.

Application of fluorocarbon nanoparticles of 131I-fulvestrant as a targeted radiation drug for endocrine therapy on human breast cancer

BACKGROUND

Breast cancer is the most prevalent malignant tumor among women, with hormone receptor-positive cases constituting 70%. Fulvestrant, an antagonist for these receptors, is utilized for advanced metastatic hormone receptor-positive breast cancer. Yet, its inhibitory effect on tumor cells is not strong, and it lacks direct cytotoxicity. Consequently, there's a significant challenge in preventing recurrence and metastasis once cancer cells develop resistance to fulvestrant.

METHOD

To address these challenges, we engineered tumor-targeting nanoparticles termed 131I-fulvestrant-ALA-PFP-FA-NPs. This involved labeling fulvestrant with 131I to create 131I-fulvestrant. Subsequently, we incorporated the 131I-fulvestrant and 5-aminolevulinic acid (ALA) into fluorocarbon nanoparticles with folate as the targeting agent. This design facilitates a tri-modal therapeutic approach-endocrine therapy, radiotherapy, and PDT for estrogen receptor-positive breast cancer.

RESULTS

Our in vivo and in vitro tests showed that the drug-laden nanoparticles effectively zeroed in on tumors. This targeting efficiency was corroborated using SPECT-CT imaging, confocal microscopy, and small animal fluorescence imaging. The 131I-fulvestrant-ALA-PFP-FA-NPs maintained stability and showcased potent antitumor capabilities due to the synergism of endocrine therapy, radiotherapy, and CR-PDT. Throughout the treatment duration, we detected no notable irregularities in hematological, biochemical, or histological evaluations.

CONCLUSION

We've pioneered a nanoparticle system loaded with radioactive isotope 131I, endocrine therapeutic agents, and a photosensitizer precursor. This system offers a combined modality of radiotherapy, endocrine treatment, and PDT for breast cancer.

Nuclear Medicine Imaging Tools in Fever of Unknown Origin (FUO): Time for a Revisit and Appropriate Use Criteria

Fever of unknown origin (FUO) is a clinical conundrum for patients and clinicians alike and imaging studies are often performed as part of the diagnostic workup of these patients. Recently, the Society of Nuclear Medicine and Molecular Imaging (SNMMI) convened and approved a guideline on the use of nuclear medicine tools for FUO. The guidelines support the use of 2-18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) in adults and children with FUO. 18F-FDG PET/CT allows the detection and localization of foci of hypermetabolic lesions with high sensitivity, based on 18F-FDG uptake in glycolytically active cells that may represent inflammation, infection, or neoplasia. Clinicians should consider and insurers should cover 18F-FDG PET/CT when evaluating patients with FUO, particularly when other clinical clues and preliminary studies are unrevealing.

Patient factors affecting 18F FDG uptake in children

PURPOSE

To characterize physiologic uptake of 18F FDG in children undergoing PET/CT as a step to informing efforts to optimize FDG PET image quality in children.

METHODS

This retrospective study included 193 clinically indicated 18F FDG PET/CT examinations from 139 patients. 3D spherical regions of interest (ROIs) in the liver and in the thigh muscle (an area of uniform low-level uptake) were used to measure counts and mean standardized uptake value by body weight (SUVmean-bw). Counts, SUVs, and liver signal to noise ratio (SNR) were assessed for associations with patient-specific predictor variables using Pearson correlation and multivariable linear regression.

RESULTS

Mean patient age was 11.0 ± 5.4 (SD) years, mean liver SUVmean-bw was 1.77 ± 0.60 and mean liver counts was 5387 ± 1875 Bq/mL. On univariable analysis liver SUVmean-bw and liver counts were strongly correlated with weight (r = 0.87, p < 0.0001), age (r = 0.75, p < 0.0001) and total injected activity (r = 0.85, p < 0.0001). Mean thigh counts were significantly associated only with injected activity/kilogram (r = 0.37, p < 0.0001). On multivariable analysis, body weight and age (which is collinear with body weight) were the only significant independent predictors (p < 0.0001). Liver SNR was moderately associated with all predictors apart from injected activity per kilogram (r = 0.09, p = 0.23).

CONCLUSION

Liver counts on 18F FDG PET/CT have a significant positive association with age and body weight. However, liver SNR has no significant association with injected activity per kilogram suggesting that increasing dose per kilogram may not improve image quality in young children.

10-year update to the combined 16-month nuclear medicine and diagnostic radiology residency: The NuRad pathway

BACKGROUND

The decline in nuclear medicine (NM) residencies in the United States has led to a shortage of NM physicians. To help address this, a 16-month NM pathway for diagnostic radiology (DR) residents was developed in 2010. At the University of Arkansas for Medical Sciences, we matched our first resident into the NuRad (NM + DR) pathway in 2013. Despite our success, we remain one of only five programs in the United States that offers a combined training pathway through the National Resident Matching Program.

OBJECTIVES

Review our 10-year experience with the NuRad pathway at UAMS and highlight the key components and significance of the 16-month NM pathway.

METHODS

Retrospective review of NRMP applicants to the DR and NuRad pathway from 2013 and 2023 at UAMS. Literature and website review of the educational structure of the 16-month NM pathway.

RESULTS

We have seen significant increase in the number of applicants to the NuRad pathway at UAMS over the last 10 years with 184 applicants for 1 position in 2023, up from 18 applicants in 2013. Furthermore, we have seen an increase in the USMLE step scores for applicants during this time.

CONCLUSIONS

There is a growing need for NM trained physicians in the United States. Over the last 10 years, we have seen increasing interest in the NM 16-month pathway as a part of DR residency. A wider implementation of this combined training pathway is needed, if we are to realize its full potential.

Multidisciplinary radio-guided surgery team: Alternative to change the current paradigm

INTRODUCTION

Given the constant increase in the healthcare demand for examinations related to radio-guided surgery (RGS), our hospital adopted new professional profiles in the RGS team, in order to partially reduce the time spent by nuclear medicine physicians on this task.

AIM

To analyze the process of incorporating the profiles of Diagnostic Imaging Technician (DIT) and Sentinel Node Referent Nurse (SNRN), evaluating their deployment in the procedures linked to the technique.

MATERIAL AND METHODS

Analysis of RGS activity during the period 2018-2022, focusing on pre-surgical and surgical procedures related to breast cancer (BC) and malignant melanoma (MM), as they are those pathologies on which the transfer of care competencies was concentrated. Chronological evolution of the competencies assumed by the different profiles during their integration into the RGS team.

RESULTS

RGS's healthcare activity during the analyzed period experienced an increase of 109%. BC and MM were the pathologies that accounted for by far the greatest demand for care. The transfer of competencies in these two pathologies occurred in a progressive and staggered manner, with 74% (460/622) of the administration phase being carried out by the SNRN and 64% (333/519) of the surgeries by the DIT in 2022.

CONCLUSIONS

The creation of a multidisciplinary RGS team that includes different professional profiles (nuclear medicine physician [MN], ERGC and TSID) is an effective strategy to respond to the increase in the complexity and number of all procedures related to RGS.

Advancements in the development of radiopharmaceuticals for nuclear medicine applications in the treatment of bone metastases

Bone metastases are a painful and complex condition that overwhelmingly impacts the prognosis and quality of life of cancer patients. Over the years, nuclear medicine has made remarkable progress in the diagnosis and management of bone metastases. This review aims to provide a comprehensive overview of the recent advancements in nuclear medicine for the diagnosis and management of bone metastases. Furthermore, the review explores the role of targeted radiopharmaceuticals in nuclear medicine for bone metastases, focusing on radiolabeled molecules that are designed to selectively target biomarkers associated with bone metastases, including osteocytes, osteoblasts, and metastatic cells. The applications of radionuclide-based therapies, such as strontium-89 (Sr-89) and radium-223 (Ra-223), are also discussed. This review also highlights the potential of theranostic approaches for bone metastases, enabling personalized treatment strategies based on individual patient characteristics. Importantly, the clinical applications and outcomes of nuclear medicine in osseous metastatic disease are discussed. This includes the assessment of treatment response, predictive and prognostic value of imaging biomarkers, and the impact of nuclear medicine on patient management and outcomes. The review identifies current challenges and future perspectives on the role of nuclear medicine in treating bone metastases. It addresses limitations in imaging resolution, radiotracer availability, radiation safety, and the need for standardized protocols. The review concludes by emphasizing the need for further research and advancements in imaging technology, radiopharmaceutical development, and integration of nuclear medicine with other treatment modalities. In summary, advancements in nuclear medicine have significantly improved the diagnosis and management of osseous metastatic disease and future developements in the integration of innovative imaging modalities, targeted radiopharmaceuticals, radionuclide production, theranostic approaches, and advanced image analysis techniques hold great promise in improving patient outcomes and enhancing personalized care for individuals with bone metastases.

Container-content interactions with radiopharmaceuticals: Seeing is believing

This perspective article addresses the critical issue of container-content interactions in the administration of intravenous medications, with a focus on radiopharmaceuticals used in nuclear medicine. Medication administration errors pose a significant challenge to patient safety. The "five rights" framework-ensuring the right patient, drug, time, dose, and route-serves as a cornerstone for safe drug administration. In the context of radiopharmaceuticals, notable for their use in nuclear medicine, adherence to these principles is paramount due to their unique properties and role in diagnostic and therapeutic procedures. The article explores the impact of container materials, particularly in syringes, on radiopharmaceutical stability and administration accuracy. It delves into the complexities of sorption phenomena, highlighting studies demonstrating its occurrence and potential consequences, including variations in administered doses and compromised diagnostic or therapeutic outcomes. Noteworthy factors influencing sorption include the type of radiopharmaceutical, container composition, molecular properties, and dilution. Findings revealing residual activity in syringes and identifying specific components, such as lubricants, silicon gaskets, and plungers, contributing to adsorption are presented. Migration of metal contaminants from container to content is discussed, emphasizing the potential impact on radiochemical yield and stability. There is a need for comprehensive studies to characterize drug-container interactions and poses crucial questions about the true benefit patients derive from prescribed activities. It challenges current practices, suggesting a need for tailored activity levels, container validation protocols, and rigorous testing of hospital preparations. Ultimately, this perspective paper calls for a deeper understanding of these interactions, urging regulatory consideration and standardization to ensure optimal drug administration and patient outcomes.

Diagnostic accuracy of bone scan at different PSA levels in biochemical recurrence of prostate cancer

OBJECTIVE

To determine the diagnostic accuracy of Bone Scan at different PSA levels for detecting skeletal metastases in men with biochemical recurrence of prostate cancer.

METHODS

We conducted a retrospective review of the statewide RIS-PACS to identify 251 men with biochemical recurrence who underwent both a Bone Scan and Ga68 PSMA PET/CT (within 2 months of each other) between September 2019 and December 2022 at a single institution. The Ga68 PSMA PET/CT report was considered to be the reference standard.

RESULTS

The median age was 72 years (IQR 67-76) with a median PSA level of 1 ng/ml (IQR 0.25-2.8). Using Ga68 PSMA PET/CT as the reference standard, 68/251 patients (25%) were positive for osseus metastases. Overall sensitivity and specificity of Bone Scan was 51% (95% CI 40-64%) and 99% (95% CI 98-100%) respectively. Using PSA banding, a PSA threshold of 20 ng/ml provided the greatest discriminatory benefit with sensitivity of the Bone Scan below the threshold being 46% (95% CI 33-59%) and above the threshold being 89% (95% CI 68-100%). Specificity remained consistently high both below and above this threshold.

CONCLUSION

Bone Scan provides greater diagnostic accuracy for detecting skeletal metastases in biochemical recurrence when the PSA level is above 20 ng/ml. This knowledge is valuable in optimising imaging algorithms in biochemical recurrence, particularly in regions where PSMA PET/CT is less readily available or affordable.

Workplace violence in medical radiation science: A systematic review

INTRODUCTION

According to World Health Organization (WHO), workplace violence (WPV) is a significant issue in healthcare. However, no systematic review on WPV in medical radiation science (MRS) has been published yet. The purpose of this paper is to systematically review prevalence of WPV in MRS and its risk factors.

METHODS

Electronic scholarly publication databases, namely EBSCOhost/Cumulative Index of Nursing and Allied Health Literature Ultimate, PubMed/Medline, ScienceDirect, Scopus, and Wiley Online Library were used for literature search to identify articles about WPV in MRS published over last 10 years as per preferred reporting items for systematic reviews and meta-analyses guidelines. To facilitate comparisons of the WPV prevalence and relative importance of individual risk factors across the included studies, their reported absolute figures of findings were used to synthesize respective percentages (if not stated).

RESULTS

Twelve papers met the selection criteria and were included. This review shows that the WPV prevalence were 69.2-100 % (whole career) and 46.1-83.0 % (last 12 months) in diagnostic radiography, 63.0-84.0 % (whole career) in radiation therapy, 57.6 % in medical sonography (last 12 months), and 46.8 % (last 6 months) in nuclear medicine. The identified WPV risk factors included intoxicated patients, staff stress, feeling of inadequacy resulting in self-protection, more vulnerable practitioners (female, <40 years old and <5-year experience), working in radiation therapy treatment room, emergency department, examination room, general radiography, public hospital, and non-examination and waiting areas, long patient waiting time, night shift, overcrowding environment, unable to meet patients'/family members' expectations, miscommunication, patient handling, inadequate staff and security measures, interaction with colleagues, and lone working.

CONCLUSION

The WPV risk in diagnostic radiography and radiation therapy appears extremely high as a result of the aforementioned risk factors. Nevertheless, these study findings should be used with caution due to potential non-response bias.

IMPLICATIONS FOR PRACTICE

A WPV policy should be developed in every clinical workplace. Even if such policy is available, its enforcement including policy awareness boosting, and encouraging incident reporting and support seeking will be essential for reducing WPV. More survey studies based on WHO WPV questionnaire should be conducted for strengthening evidence base.

2-[18]F FDG PET/CT dissemination features in adult burkitt lymphoma Are predictive of outcome

This retrospective study investigated the prognostic role of disease dissemination features (Dmax and Dmaxbsa) measured by 2-[18F]FDG PET/CT in newly diagnosed Burkitt Lymphoma (BL) patients, comparing their performance with other metabolic parameters. We included 78 patients diagnosed with BL between 2010 and 2022 with an available baseline PET, interim PET/CT (iPET) and end of treatment PET/CT (eotPET) and with a minimum of two 2-[18F]FDG avid lesions present at the baseline scan. Dmax was calculated from the three-dimensional coordinates of the baseline metabolic tumor volume (MTV) by using LIFEx software; Dmaxbsa was calculated as Dmax normalized for body surface area according to the Du Bois method. We evaluated their effect on metabolic treatment response evaluated by PET, on progression free survival (PFS) and on overall survival (OS). Dmaxbsa was significantly associated with tumor stage, bulky and extranodal disease, MTV and TLG. At a median follow-up of 49 months, the median PFS and OS were 45 and 48 months. Dmax and Dmaxbsa were significantly higher in not complete metabolic response than complete metabolic response group at iPET and eotPET.As far as PFS, parameters including iPET/CT, eotPET/CT outcomes, MTV and TLG showed to be independent prognostic factors while Dmax and Dmaxbsa were not significantly associated with the outcome. Dissemination features, together with eotPET/CT results, MTV and TLG, demonstrated to be significantly correlated with OS. In conclusion, in this study we demonstrated that dissemination features derived by 2[18F]-FDG PET/CT were significantly correlated with response to treatment and long-term outcome, independently from other PET features.

A patient journey audit tool (PJAT) to assess quality indicators in a nuclear medicine service

PURPOSE

To develop a nuclear medicine specific patient journey audit tool (PJAT) to survey and audit patient journeys in a nuclear medicine department such as staff interaction with patients, equipment, quality of imaging and laboratory procedures, patient protection, infection control and radiation safety, with a view to optimising patient care and providing a high-quality nuclear medicine service.

METHODS

The PJAT was developed specifically for use in nuclear medicine practices. Thirty-two questions were formulated in the PJAT to test the department's compliance to the Australian National Safety and Quality Health Service Standards, namely clinical governance, partnering with consumers, preventing and controlling health care infection, medication safety, comprehensive care, communicating for safety, blood management and recognising and responding to acute deterioration. The PJAT was also designed to test our department's adherence to diagnostic reference levels (DRL). A total of 60 patient journey audits were completed for patients presenting for nuclear medicine, positron emission tomography and bone mineral density procedures during a consecutive 4-week period to audit the range of procedures performed. A further 120 audits were captured for common procedures in nuclear medicine and positron emission tomography during the same period. Thus, a total of 180 audits were completed. A subset of 12 patients who presented for blood labelling procedures were audited to solely assess the blood management standard.

RESULTS

The audits demonstrated over 85% compliance for the Australian national health standards. One hundred percent compliance was noted for critical aspects such as correct patient identification for the correct procedure prior to radiopharmaceutical administration, adherence to prescribed dose limits and distribution of the report within 24 h of completion of the imaging procedure.

CONCLUSION

This PJAT can be applied in nuclear medicine departments to enhance quality programmes and patient care. Austin Health has collaborated with the IAEA to formulate the IAEA PJAT, which is now available globally for nuclear medicine departments to survey patient journeys.

Empowering PET: harnessing deep learning for improved clinical insight

This review aims to take a journey into the transformative impact of artificial intelligence (AI) on positron emission tomography (PET) imaging. To this scope, a broad overview of AI applications in the field of nuclear medicine and a thorough exploration of deep learning (DL) implementations in cancer diagnosis and therapy through PET imaging will be presented. We firstly describe the behind-the-scenes use of AI for image generation, including acquisition (event positioning, noise reduction though time-of-flight estimation and scatter correction), reconstruction (data-driven and model-driven approaches), restoration (supervised and unsupervised methods), and motion correction. Thereafter, we outline the integration of AI into clinical practice through the applications to segmentation, detection and classification, quantification, treatment planning, dosimetry, and radiomics/radiogenomics combined to tumour biological characteristics. Thus, this review seeks to showcase the overarching transformation of the field, ultimately leading to tangible improvements in patient treatment and response assessment. Finally, limitations and ethical considerations of the AI application to PET imaging and future directions of multimodal data mining in this discipline will be briefly discussed, including pressing challenges to the adoption of AI in molecular imaging such as the access to and interoperability of huge amount of data as well as the "black-box" problem, contributing to the ongoing dialogue on the transformative potential of AI in nuclear medicine.Relevance statementAI is rapidly revolutionising the world of medicine, including the fields of radiology and nuclear medicine. In the near future, AI will be used to support healthcare professionals. These advances will lead to improvements in diagnosis, in the assessment of response to treatment, in clinical decision making and in patient management.Key points• Applying AI has the potential to enhance the entire PET imaging pipeline.• AI may support several clinical tasks in both PET diagnosis and prognosis.• Interpreting the relationships between imaging and multiomics data will heavily rely on AI.

A look at radiation detectors and their applications in medical imaging

The effectiveness and precision of disease diagnosis and treatment have increased, thanks to developments in clinical imaging over the past few decades. Science is developing and progressing steadily in imaging modalities, and effective outcomes are starting to show up as a result of the shorter scanning periods needed as well as the higher-resolution images generated. The choice of one clinical device over another is influenced by technical disparities among the equipment, such as detection medium, shorter scan time, patient comfort, cost-effectiveness, accessibility, greater sensitivity and specificity, and spatial resolution. Lately, computational algorithms, artificial intelligence (AI), in particular, have been incorporated with diagnostic and treatment techniques, including imaging systems. AI is a discipline comprised of multiple computational and mathematical models. Its applications aided in manipulating sophisticated data in imaging processes and increased imaging tests' accuracy and precision during diagnosis. Computed tomography (CT), positron emission tomography (PET), and Single Photon Emission Computed Tomography (SPECT) along with their corresponding radiation detectors have been reviewed in this study. This review will provide an in-depth explanation of the above-mentioned imaging modalities as well as the radiation detectors that are their essential components. From the early development of these medical instruments till now, various modifications and improvements have been done and more is yet to be established for better performance which calls for a necessity to capture the available information and record the gaps to be filled for better future advances.

Molecular imaging and related therapeutic options for medullary thyroid carcinoma: state of the art and future opportunities

Due to its rarity and non-specific clinical presentation, accurate diagnosis, and optimal therapeutic strategy of medullary thyroid carcinoma (MTC) remain challenging. Molecular imaging provides valuable tools for early disease detection, monitoring treatment response, and guiding personalized therapies. By enabling the visualization of molecular and cellular processes, these techniques contribute to a deeper understanding of disease mechanisms and the development of more effective clinical interventions. Different nuclear imaging techniques have been studied for assessing MTC, and among them, PET/CT utilizing multiple radiotracers has emerged as the most effective imaging method in clinical practice. This review aims to provide a comprehensive summary of the current use of advanced molecular imaging modalities, with a particular focus on PET/CT, for the management of patients with MTC. It aims to guide physicians towards a rationale for the use of molecular imaging also including theranostic approaches and novel therapeutical opportunities. Overall, we emphasize the evolving role of nuclear medicine in MTC. The integration of diagnostics and therapeutics by in vivo molecular imaging represents a major opportunity to personalize treatment for individual patients, with targeted radionuclide therapy being one representative example.

Validation of a discovery MI 4-ring model according to the NEMA NU 2-2018 standards: from Monte Carlo simulations to clinical-like reconstructions

BACKGROUND

We propose a comprehensive evaluation of a Discovery MI 4-ring (DMI) model, using a Monte Carlo simulator (GATE) and a clinical reconstruction software package (PET toolbox). The following performance characteristics were compared with actual measurements according to NEMA NU 2-2018 guidelines: system sensitivity, count losses and scatter fraction (SF), coincidence time resolution (CTR), spatial resolution (SR), and image quality (IQ). For SR and IQ tests, reconstruction of time-of-flight (TOF) simulated data was performed using the manufacturer's reconstruction software.

RESULTS

Simulated prompt, random, true, scatter and noise equivalent count rates closely matched the experimental rates with maximum relative differences of 1.6%, 5.3%, 7.8%, 6.6%, and 16.5%, respectively, in a clinical range of less than 10 kBq/mL. A 3.6% maximum relative difference was found between experimental and simulated sensitivities. The simulated spatial resolution was better than the experimental one. Simulated image quality metrics were relatively close to the experimental results.

CONCLUSIONS

The current model is able to reproduce the behaviour of the DMI count rates in the clinical range and generate clinical-like images with a reasonable match in terms of contrast and noise.

Radionuclide Reporter Imaging to Visualize Tumor Hypoxia Ex Vivo and In Vivo

In vitro studies using cell culture, including three-dimensional cultures without the involvement of tumor vessels, have limitations in simulating complex intratumoral hypoxic conditions in live subjects. To generate experimental hypoxic conditions closer to those observed in humans in clinical settings, in vivo studies are necessary. In addition, visible light generated via bioluminescence and fluorescence is generally unsuitable for in vivo experiments because of low tissue penetration. Furthermore, near-infrared light (NIR), which has the highest tissue penetration among lights of different wavelengths, cannot be assessed precisely in vivo because of the difficulty in correcting tissue absorption and scatter. For in vivo quantitative analyses, imaging modalities that use high tissue-penetrating signals, such as computed tomography (CT) using X-rays, radionuclide imaging using γ-rays, and magnetic resonance imaging (MRI) using electromagnetic waves, are ideal.Therefore, as an advanced protocol for this research purpose, we provide ex vivo and in vivo methods to investigate the genetic response of multiple copies of hypoxia response elements (HREs) to tumor hypoxia in terms of intensity and intratumoral distribution using a human sodium/iodide symporter (hNIS) reporter gene and radionuclide reporter probes (radioiodine and its chemical analog Tc-99m) based on our previous research. This protocol includes cloning an hNIS reporter construct with multiple copies of HREs, establishing stable cell lines of the reporter construct, preparing a mouse subcutaneous xenograft model, and evaluating the genetic response of multiple HREs to tumor hypoxia using digital autoradiography (ARG) ex vivo and using single-photon emission computed tomography (SPECT) or positron emission tomography (PET) in vivo.

Evaluation of personal dose equivalents during positron emission tomography and computed tomography imaging

This study aimed to evaluate the annual occupational radiation exposure of technologists during PET/CT imaging in 2020 and 2021. Eleven nuclear medicine technologists were monitored at the PET/CT department. The personal dose equivalents (PDEs) for staff members, measured in terms of Hp (10) and Hp (0.07), were assessed annually, considering both deep and surface doses. PDEs were quantified using a thermoluminescent detector (LiF:Mg:Ti)). The average and range of PDEs and extremity doses (mSv) for the technologists were as follows: 4.5 (0.1-13.4) for Hp (10), 4.63 (0.1-13.9) for Hp (0.07), and 2.5 (0.2-17.5) for extremity, respectively. The results indicated that staff members are exposed to high-energy gamma rays while preparing radiopharmaceuticals, injections, and image acquisition. Therefore, proper handling of radiopharmaceuticals and patient management during the acquisition of parameters are crucial for maintaining the occupational dose within the defined limit.

European Association of Nuclear Medicine Focus 5: Consensus on Molecular Imaging and Theranostics in Prostate Cancer

BACKGROUND

In prostate cancer (PCa), questions remain on indications for prostate-specific membrane antigen (PSMA) positron emission tomography (PET) imaging and PSMA radioligand therapy, integration of advanced imaging in nomogram-based decision-making, dosimetry, and development of new theranostic applications.

OBJECTIVE

We aimed to critically review developments in molecular hybrid imaging and systemic radioligand therapy, to reach a multidisciplinary consensus on the current state of the art in PCa.

DESIGN, SETTING, AND PARTICIPANTS

The results of a systematic literature search informed a two-round Delphi process with a panel of 28 PCa experts in medical or radiation oncology, urology, radiology, medical physics, and nuclear medicine. The results were discussed and ratified in a consensus meeting.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Forty-eight statements were scored on a Likert agreement scale and six as ranking options. Agreement statements were analysed using the RAND appropriateness method. Ranking statements were analysed using weighted summed scores.

RESULTS AND LIMITATIONS

After two Delphi rounds, there was consensus on 42/48 (87.5%) of the statements. The expert panel recommends PSMA PET to be used for staging the majority of patients with unfavourable intermediate and high risk, and for restaging of suspected recurrent PCa. There was consensus that oligometastatic disease should be defined as up to five metastases, even using advanced imaging modalities. The group agreed that [177Lu]Lu-PSMA should not be administered only after progression to cabazitaxel and that [223Ra]RaCl2 remains a valid therapeutic option in bone-only metastatic castration-resistant PCa. Uncertainty remains on various topics, including the need for concordant findings on both [18F]FDG and PSMA PET prior to [177Lu]Lu-PSMA therapy.

CONCLUSIONS

There was a high proportion of agreement among a panel of experts on the use of molecular imaging and theranostics in PCa. Although consensus statements cannot replace high-certainty evidence, these can aid in the interpretation and dissemination of best practice from centres of excellence to the wider clinical community.

PATIENT SUMMARY

There are situations when dealing with prostate cancer (PCa) where both the doctors who diagnose and track the disease development and response to treatment, and those who give treatments are unsure about what the best course of action is. Examples include what methods they should use to obtain images of the cancer and what to do when the cancer has returned or spread. We reviewed published research studies and provided a summary to a panel of experts in imaging and treating PCa. We also used the research summary to develop a questionnaire whereby we asked the experts to state whether or not they agreed with a list of statements. We used these results to provide guidance to other health care professionals on how best to image men with PCa and what treatments to give, when, and in what order, based on the information the images provide.

Augmented reality for sentinel lymph node biopsy

INTRODUCTION

Sentinel lymph node biopsy for oral and oropharyngeal squamous cell carcinoma is a well-established staging method. One variation is to inject a radioactive tracer near the primary tumor of the patient. After a few minutes, audio feedback from an external hand-held [Formula: see text]-detection probe can monitor the uptake into the lymphatic system. Such probes place a high cognitive load on the surgeon during the biopsy, as they require the simultaneous use of both hands and the skills necessary to correlate the audio signal with the location of tracer accumulation in the lymph nodes. Therefore, an augmented reality (AR) approach to directly visualize and thus discriminate nearby lymph nodes would greatly reduce the surgeons' cognitive load.

MATERIALS AND METHODS

We present a proof of concept of an AR approach for sentinel lymph node biopsy by ex vivo experiments. The 3D position of the radioactive [Formula: see text]-sources is reconstructed from a single [Formula: see text]-image, acquired by a stationary table-attached multi-pinhole [Formula: see text]-detector. The position of the sources is then visualized using Microsoft's HoloLens. We further investigate the performance of our SLNF algorithm for a single source, two sources, and two sources with a hot background.

RESULTS

In our ex vivo experiments, a single [Formula: see text]-source and its AR representation show good correlation with known locations, with a maximum error of 4.47 mm. The SLNF algorithm performs well when only one source is reconstructed, with a maximum error of 7.77 mm. For the more challenging case to reconstruct two sources, the errors vary between 2.23 mm and 75.92 mm.

CONCLUSION

This proof of concept shows promising results in reconstructing and displaying one [Formula: see text]-source. Two simultaneously recorded sources are more challenging and require further algorithmic optimization.

The radiology job market in the Netherlands: which subspecialties and other skills are in demand?

OBJECTIVES

To evaluate the current job market for medical specialists in radiology and nuclear medicine (NM) in the Netherlands.

METHODS

Vacancies posted for radiologists and nuclear medicine physicians in the Netherlands between December 2020 and February 2022 were collected and analyzed.

RESULTS

A total of 157 vacancies (146 for radiologist and 11 for nuclear medicine physicians) were included. The most sought-after subspecialties were all-round (22%), abdominal (19%), and interventional radiology (14%), and 30% of vacancies preferred applicants with additional non-clinical skills (research, teaching, management, information and communications technology (ICT)/artificial intelligence (AI)). Non-academic hospitals significantly more frequently requested all-round radiologists (n = 31) than academic hospitals (n = 1) (p = 0.001), while the distribution of other requested subspecialties was not significantly different between non-academic and academic vacancies. Non-academic hospitals also significantly more frequently requested additional research tasks in their vacancies (n = 35) compared to academic hospitals (n = 4) (p = 0.011). There were non-significant trends for non-academic hospitals more frequently requesting teaching tasks in their vacancies (n =18) than academic hospitals (n = 1) (p = 0.051), and for non-academic hospitals more frequently asking for management skills (n = 11) than academic hospitals (n = 0) (p = 0.075).

CONCLUSION

All-round, abdominal, and interventional radiologists are most in demand on the job market in the Netherlands. All-round radiologists are particularly sought after by non-academic hospitals, whereas nuclear radiologists who completed the Dutch integrated NM and radiology residency seem to be welcomed by hospitals searching for a nuclear medicine specialist. Finally, non-clinical skills (research, teaching, management, ICT/AI) are commonly requested. These data can be useful for residents and developers of training curricula.

CLINICAL RELEVANCE STATEMENT

An overview of the radiology job market and the requested skills is important for residents, for those who seek work as a radiologist, and for those who are involved in the design and revision of residency programs.

KEY POINTS

Review of job vacancies over an extended period of time provides valuable information to residents and feedback to potentially improve radiology and nuclear medicine (NM) residency programs. All-round radiologists are wanted in non-academic hospitals and nuclear radiologists (those who have completed an integrated NM-radiology curriculum) are welcomed by hospitals searching for nuclear medicine specialists in the Netherlands. There is a need to train residents in important non-clinical skills, such as research and teaching, but also management and communications technology/artificial intelligence.

Assessment of awareness and knowledge regarding nuclear medicine and appropriate use of Nuclear medicine modalities, among medical students and faculty members in two academic medical institutes in North India: A Cross sectional Study

Objectives

Despite significant progress in the field of nuclear medicine, basic nuclear medicine awareness and understanding among clinicians remains unsatisfactory, leading to under utilization of nuclear medicine modalities. To evaluate the awareness and knowledge regarding nuclear medicine and appropriate use of Nuclear medicine modalities, among medical students and faculty members.

Method

In this descriptive cross sectional study, a self timer limited objective questionnaire based on Google forms was distributed to the study population and scores obtained by the participants were analyzed.

Results

Percent scores range for intern, residency trainees, and senior resident/faculty groups for general awareness were 16-46%, 37-58% and 62-91% and for knowledge and appropriate use were 7-21%, 28-43%, and 35-85% respectively. Overall, 61% of the participants had poor awareness and knowledge regarding nuclear medicine modalities. None of the participants had received nuclear medicine exposure or education during their academics or training. Only 49% of the participants considered utilizing nuclear medicine modalities for their patient management.

Conclusion

Undergraduate interns and residency trainees had a poor to fair level of awareness and knowledge regarding nuclear medicine. Hence creating more awareness in early stages of their career by incorporating Nuclear medicine basic education in medical undergraduate curriculum is required. The senior residents/faculty members had a moderate to good level of awareness and knowledge but still improvement in their knowledge would lead to a more appropriate and better utilization of nuclear medicine modalities for optimum patient management in a variety of clinical settings.

Accuracy of skeletal scintigraphy for the evaluation of mandibular growth disorders: a systematic review

Bone scans, reflecting blood flow and metabolic activity in a region of interest, are frequently used to evaluate mandibular growth disorders. Increased uptake is a non-specific finding and can occur as a result of multiple causes. The correlation between radioactive tracer uptake and growth activity has not been consistently demonstrated. The aim of this study was to assess the accuracy of planar skeletal scintigraphy (SS), single-photon emission computed tomography (SPECT), and SPECT with computed tomography (CT) images (SPECT/CT) in detecting abnormal mandibular growth activity compared to clinical and radiographic/tomographic methods (reference standard) and histologic findings. A systematic review was conducted following the PRISMA guidelines. Sensitivity, specificity, and accuracy were calculated for planar SS, SPECT, and SPECT/CT. Compared to the reference standard, SPECT/CT had the best diagnostic accuracy (76.5% sensitivity, 90.4% specificity, 83.2% accuracy), followed by planar SS (81.8% sensitivity, 84.5% specificity, 83.0% accuracy) and SPECT (77.7% sensitivity, 72.4% specificity, 74.5% accuracy). The results of this study indicate that SPECT/CT has the best clinical correlation, but the certainty of the evidence is low. The differences in sensitivity and specificity between the three index tests were not clinically significant. The three tests can be useful, with only a small difference in their diagnostic value. Histopathology was found not to be satisfactory as a reference standard.

[Pain reduction by radiosynoviorthesis in rheumatism-induced synovitis of the elbow : Results of a retrospective multicenter data analysis]

BACKGROUND

Radiosynoviorthesis (RSO) is a nuclear medical local treatment modality for inflammatory joint diseases. It is indicated in patients with rheumatoid arthritis (RA) in joints with persistent synovitis despite adequate pharmacotherapy. Arthritis of the elbow joint occurs in up to 2/3 of patients with RA. Intra-articular radiotherapy using the beta emitter [186Re] rhenium sulfide leads to sclerosis of the inflamed synovial membrane with subsequent pain alleviation. The clinical efficacy in cubital arthritis, however, has so far only been described in small monocentric studies.

OBJECTIVE

The degree of pain alleviation by RSO was analyzed in patients with rheumatoid cubital arthritis, treated in several nuclear medical practices specialized in RSO.

MATERIAL AND METHODS

The subjective pain intensity before and after RSO was documented in a total of 107 patients with rheumatic cubital arthritis using a 10-step numeric rating scale (NRS). A difference of ≥ -2 is rated as a significant improvement. Follow-up examinations were done after a mean interval of 14 months after RSO (at least 3 months, maximum 50 months).

RESULTS

The mean NRS value was 7.3 ± 2.1 before RSO and 2.8 ± 2.2 after RSO. A significant pain alleviation was seen in 78.5% of all patients treated. The subgroup analysis also showed a significant improvement in the pain symptoms in all groups depending on the time interval between the RSO and the control examination. A significant pain progression was not observed. The degree of pain relief was independent of the time of follow-up.

CONCLUSION

Using RSO for local treatment of rheumatoid cubital arthritis leads to a significant and long-lasting pain relief in more than ¾ of the treated patients.

Comparison of serum creatinine, point-of-care symmetric dimethylarginine and renal imaging with glomerular filtration rate measured by renal scintigraphy in healthy and early chronic kidney diseased cats

The aim of this study was to evaluate routinely used tests to diagnose cats in early stages of chronic kidney disease (CKD) and to describe a model for evaluating these variables simultaneously. Apparently healthy cats were screened using serum creatinine (sCr), point-of-care symmetric dimethylarginine (POC SDMA), urinalysis, urine protein/creatinine ratio (UPC) and imaging evaluation. Those parameters were compared to glomerular filtration rate (GFR) assessed by renal scintigraphy. Forty-four cats were included and consisted of 14 (31.8%) healthy cats (absence of abnormalities in renal morphology and sCr less than 1.6 mg/dL), 20 (45.5%) cats classified as CKD I (presence of abnormalities in renal morphology and sCr less than 1.6 mg/dL) and ten (22.7%) as CKD II (sCr equal to or greater than 1.6 mg/dL, with or without abnormalities in renal morphology). A large number (40.9%) of apparently healthy cats presented reduction in GFR, which included half of CKD I patients. Point-of-care SDMA was not a good predictor for decreased GFR, nor was it correlated with the variables GFR and sCr. Glomerular filtration rate was significantly lower in CKD I and II groups in comparison with healthy cats, but there was no significant difference between the CKD I and II groups. Multivariate logistic regression model identified three variables that affected the odds of a cat having decreased GFR (< 2.5 mL/min/kg): sCr (OR = 18.3; p = 0.019; CI = 1.6-207.2), and the ultrasonographic findings 'reduced corticomedullary definition' (OR = 19.9; p = 0.022; CI = 1.6-254.0) and 'irregular contour' (OR = 65.6; p = 0.003; CI = 4.2-1038.2). Renal ultrasonography evaluation should always be considered for screening early CKD in apparently healthy cats.

Proposal for a Display Method for Myocardial Single Photon Emission Computed Tomography Based on Left Ventricular Volume

Bull's eye view for the display of myocardial single-photon emission computed tomography (SPECT) 3-D perfusion maps does not reflect left ventricular (LV) volume, an important parameter. We created and evaluated a myocardial SPECT display method that reflects the LV volume.Using Digital Imaging and Communications in Medicine data, short-axis slices from the apex to the base were reconstructed and interpolated into 0.5-mm thickness. We obtained the radial lengths at 1° intervals throughout 360°, and calculated the length of the LV long axis and half circumference (1/2 circ). Myocardial perfusion was displayed as 2 ellipsoidal developments that exhibited the left anterior descending coronary artery (LAD) and non-LAD regions. We created a system that can display these processes on a personal computer. Myocardial SPECT data from 526 individuals without heart disease were analyzed. The long axis and 1/2 circ were compared with the body size, LV end-diastolic diameter (LVDd) obtained by echocardiography, and the end-diastolic volume (EDV) obtained by electrocardiogram-gated SPECT analysis. The 1/2 circle correlated with the LVDd and EDV. The images obtained allowed a diagnosis comparable to that made using the conventional coordinate display system.The new myocardial display reflects ischemia and LV volume within a single image, which cannot be achieved with conventional SPECT image display. Additional studies of this display system are required to allow its application to patients with heart disease.

Radiation exposure assessment of nuclear medicine staff administering [177Lu]Lu-DOTA-TATE with active and passive dosimetry

BACKGROUND

The use of lutetium-177 (177Lu)-based radiopharmaceuticals in peptide receptor nuclear therapy is increasing, but so is the number of nuclear medicine workers exposed to higher levels of radiation. In recent years, [177Lu]Lu-DOTA-TATE has begun to be widely used for the treatment of neuroendocrine tumours. However, there are few studies evaluating the occupational radiation exposure during its administration, and there are still some challenges that can result in higher doses to the staff, such as a lack of trained personnel or fully standardised procedures. In response, this study aims to provide a comprehensive analysis of occupational doses to the staff involved in the administration of [177Lu]Lu-DOTA-TATE.

RESULTS

A total of 32 administrations of [177Lu]Lu-DOTA-TATE (7.4 GBq/session) carried out by a physician and a nurse, were studied. In total, two physicians and four nurses were independently monitored with cumulative (passive) and/or real-time (active) dosemeters. Extremity, eye lens and whole-body doses were evaluated in terms of the dosimetric quantities Hp(0.07), Hp(3) and Hp(10), respectively. It was obtained that lead aprons reduced dose rates and whole-body doses by 71% and 69% for the physicians, respectively, and by 56% and 68% for the nurses. On average, normalised Hp(10) values of 0.65 ± 0.18 µSv/GBq were obtained with active dosimetry, which is generally consistent with passive dosemeters. For physicians, the median of the maximum normalised Hp(0.07) values was 41.5 µSv/GBq on the non-dominant hand and 45.2 µSv/GBq on the dominant hand. For nurses 15.4 µSv/GBq on the non-dominant and 13.9 µSv/GBq on the dominant hand. The ratio or correction factor between the maximum dose measured on the hand and the dose measured on the base of the middle/ring finger of the non-dominant hand resulted in a factor of 5/6 for the physicians and 3/4 for the nurses. Finally, maximum normalised Hp(3) doses resulted in 2.02 µSv/GBq for physicians and 1.76 µSv/GBq for nurses.

CONCLUSIONS

If appropriate safety measures are taken, the administration of [177Lu]Lu-DOTA-TATE is a safe procedure for workers. However, regular monitoring is recommended to ensure that the annual dose limits are not exceeded.

EANM procedural recommendations for managing the paediatric patient in diagnostic nuclear medicine

PURPOSE

The manuscript aims to characterize the principles of best practice in performing nuclear medicine procedures in paediatric patients. The paper describes all necessary technical skills that should be developed by the healthcare professionals to ensure the best possible care in paediatric patients, as it is particularly challenging due to psychological and physical conditions of children.

METHODS

We performed a comprehensive literature review to establish the most relevant elements of nuclear medicine studies in paediatric patients. We focused the attention to the technical aspects of the study, such as patient preparation, imaging protocols, and immobilization techniques, that adhere to best practice principles. Furthermore, we considered the psychological elements of working with children, including comforting and distraction strategies.

RESULTS

The extensive literature review combined with practical conclusions and recommendations presented and explained by the authors summarizes the most important principles of the care for paediatric patient in the nuclear medicine field.

CONCLUSION

Nuclear medicine applied to the paediatric patient is a very special and challenging area, requiring proper education and experience in order to be performed at the highest level and with the maximum safety for the child.

[Opportunities for prostate-specific membrane antigen hybrid imaging in prostate cancer]

Prostate-specific membrane antigen (PSMA) hybrid imaging is a promising new technique gaining importance in the field of prostate cancer (PCa) diagnosis and treatment planning. By combining PSMA radioligands and computed tomography (CT) or magnetic resonance imaging (MRI), PSMA hybrid imaging opens up new diagnostic opportunities. PSMA-PET/CT (PET: positron-emission tomography) is already well established in high-risk PCa for primary staging and tumor localization when biochemical recurrence occurs. Further potential indications for PSMA-PET/CT include tumor detection in the initial work-up before a rebiopsy with improved accuracy, the identification of target structures for precise local treatment in recurrent PCa (salvage radiotherapy or radio-guided surgery) as well as a prediction of response to PSMA radioligand therapy. This narrative review is based on a recent literature search and aims to highlight the opportunities of PSMA imaging in different disease stages of PCa.

Thyroid volume is the key predictor of hyperthyroidism remission after radioactive iodine therapy in pediatric patients

Graves' disease (GD) is the leading cause of hyperthyroidism in pediatric patients. Radioactive iodine therapy (RAIT) is widely used to treat GD. However, it is still unclear exactly what determines the efficacy of RAIT in childhood and adolescence. The objective of our study was to reveal the most significant predictors of the efficacy of RAIT in pediatric GD patients. A single-center prospective observational exploratory study enrolled 144 pediatric patients (124 females and 20 males) between 8 and 18 years of age who underwent dosimetry-guided RAIT for GD for the first time. The estimated parameters included sex, age, thyroid volume, thyroid stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone receptor antibodies (TRABs) at baseline and 12 months after RAIT, 10- to 20-min 99mTc thyroid uptake (%), maximum thyroid 131I uptake (%), specific 131I uptake (MBq/g), and therapeutic activity of 131I (MBq), which was limited to 1100 MBq. The Fisher's exact test, Mann-Whitney U-test, Wilcoxon signed-rank test, ROC analysis, and the Youden index were used for statistical analysis. Twelve months after RAIT, 119 patients (83%) successfully achieved remission, 6 patients (4%) had euthyroidism, and hyperthyroidism persisted in 19 patients (13%). Thyroid volume decreased from 17.6 [14.6; 24.1] to 9.3 [7.6; 13.3] mL 12 months after the treatment (p < 0.001). The main predictor that showed a statistically significant difference between the groups of patients who achieved and did not achieve remission of GD hyperthyroidism after RAIT was the initial thyroid volume. Using the Youden index, the optimal cut-off point for the initial thyroid volume at 45.4 mL was determined.     Conclusion: The dosimetry-guided RAIT in pediatric GD patients was 83% effective at 12 months after the treatment, and the initial thyroid volume of less than 45.4 mL was the most important predictor of RAIT success. Other predictors identified in our work included FT4 levels, TRABs levels, 99mTc-pertechnetate uptake, and specific 131I uptake. What is Known: •Radioiodine therapy is a common, effective, and safe treatment for pediatric patients with Graves' disease. What is New: •The initial thyroid volume in pediatric GD patients is an important predictor of achieving hypothyroidism following radioiodine therapy. If the thyroid volume is less than 45.4 ml, radioiodine therapy limited to 1100 MBq will be effective definitive treatment.

Inspired by novel radiopharmaceuticals: Rush hour of nuclear medicine

Nuclear medicine plays an irreplaceable role in the diagnosis and treatment of tumors. Radiopharmaceuticals are important components of nuclear medicine. Among the radiopharmaceuticals approved by the Food and Drug Administration (FDA), radio-tracers targeting prostate-specific membrane antigen (PSMA) and somatostatin receptor (SSTR) have held essential positions in the diagnosis and treatment of prostate cancers and neuroendocrine neoplasms, respectively. In recent years, FDA-approved serials of immune-therapy and targeted therapy drugs targeting programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1), human epidermal growth factor receptor 2 (HER2), and nectin cell adhesion molecule 4 (Nectin 4). How to screen patients suitable for these treatments and monitor the therapy? Nuclear medicine with specific radiopharmaceuticals can visualize the expression level of those targets in systemic lesions and evaluate the efficacy of treatment. In addition to radiopharmaceuticals, imaging equipment is also a key step for nuclear medicine. Advanced equipment including total-body positron emission tomography/computed tomography (PET/CT) and positron emission tomography/magnetic resonance imaging (PET/MRI) has been developed, which contribute to the diagnosis and treatment of tumors, as well as the development of new radiopharmaceuticals. Here, we conclude most recently advances of radiopharmaceuticals in nuclear medicine, and they substantially increase the "arsenal" of clinicians for tumor therapy.

Highlight selection of radiochemistry and radiopharmacy developments by editorial board

BACKGROUND

The Editorial Board of EJNMMI Radiopharmacy and Chemistry releases a biannual highlight commentary to update the readership on trends in the field of radiopharmaceutical development.

MAIN BODY

This selection of highlights provides commentary on 21 different topics selected by each coauthoring Editorial Board member addressing a variety of aspects ranging from novel radiochemistry to first-in-human application of novel radiopharmaceuticals.

CONCLUSION

Trends in radiochemistry and radiopharmacy are highlighted. Hot topics cover the entire scope of EJNMMI Radiopharmacy and Chemistry, demonstrating the progress in the research field in many aspects.

Separation of cyclotron-produced cobalt-55/58m from iron targets using cation exchange chromatography with non-aqueous solvents and extraction chromatography

Cobalt-55 and -58m form a theranostic pair that has relevant properties for cancer research. We report a cation exchange chromatography/extraction chromatography method that separates cyclotron-produced 55/58mCo from 54/57Fe in <1.5 h, recovers >85% Co and achieves [55Co]Co-NOTA and -DOTA AMA 89 ± 48 and 35 ± 7 MBq/nmol (EOB), respectively. Cobalt-55 and -58m were quantitatively labeled to functionalized NOTA at 106 and 50 MBq/nmol (EOB), respectively, corroborating measured AMA. This method is faster than previously published methods and achieves better [55/58mCo]Co-NOTA and -DOTA AMA.

Pediatric neuroimaging in pre-CT era: back to the future

Over the last half a century, diagnostic neuroimaging has made tremendous strides following the introduction of computerized tomography (CT) and subsequent magnetic resonance imaging (MR). Prior to that time, the neurological diagnosis was conducted with careful history taking, physical examinations, and invasive testing such as cerebral angiography, encephalography, and myelography. Techniques and contrast media for these tests have been refined and progressed over time. However, these invasive tests have diminished and are rarely used for daily practice in pediatric neurosurgery since the introduction of CT and MR. Nuclear brain scan and ultrasonography are non-invasive. A nuclear brain scan using radioactive tracers was used to demonstrate the laterality of the lesion without an intact blood-brain barrier, but was rarely performed after the CT era. On the other hand, improved ultrasonography made strides because of its portability and the lack of radiation exposure and sedation. It is often a first-line investigatory tool for neonatal evaluation. This article describes a review of developments and progresses of pediatric neuroimaging in the pre-CT era.

Maximum and mean standardized uptake values of medication-related osteonecrosis of the jaw with bone SPECT/CT: comparison of mandibular pathologies, control and temporomandibular joints

OBJECTIVE

Recently, single-photon emission CT/CT (SPECT/CT) plays an important role in assessing patients with medication-related osteonecrosis of the jaw (MRONJ). The aim of this study was to investigate maximum and mean standardized uptake values (SUVs) of MRONJ with bone SPECT/CT, especially comparison of mandibular pathologies, control and temporomandibular joints.

METHODS

61 mandibular patients with MRONJ who underwent bone SPECT/CT were included in this study. The maximum and mean SUVs of the lesion, right and left sides of the lesion, opposite side of the lesion as control, right and left temporomandibular joints were analyzed using a workstation and software. The SUVs of MRONJ were analyzed using one-way analysis of variance with Tukey's honestly significant difference test. Patient characteristics with MRONJ and SUVs were analyzed using Mann-Whitney U test. P-values less than 0.05 were considered to indicate statistical significance.

RESULTS

The maximum and mean SUVs for opposite side of the lesions (4.4 ± 2.0 and 1.8 ± 0.7) were significantly lower than those for mandibular lesions (18.3 ± 8.1 and 6.3 ± 2.8), right side of the lesions (8.1 ± 3.9 and 2.9 ± 1.3) and left side of the lesions (8.1 ± 3.9 and 2.8 ± 1.4), respectively. The maximum and mean SUVs for right and left sides of the lesions, and opposite side of the lesions, right and left temporomandibular joints were not significant difference. Furthermore, the maximum SUVs of the mandibular lesions were a significant difference for age and staging.

CONCLUSIONS

The maximum and mean SUVs with SPECT/CT can be useful in the quantitative management of MRONJ patients.

Research Progress of CXCR4-Targeting Radioligands for Oncologic Imaging

C-X-C motif chemokine receptor 4 (CXCR4) plays a key role in various physiological functions, such as immune processes and disease development, and can influence angiogenesis, proliferation, and distant metastasis in tumors. Recently, several radioligands, including peptides, small molecules, and nanoclusters, have been developed to target CXCR4 for diagnostic purposes, thereby providing new diagnostic strategies based on CXCR4. Herein, we focus on the recent research progress of CXCR4-targeting radioligands for tumor diagnosis. We discuss their application in the diagnosis of hematological tumors, such as lymphomas, multiple myelomas, chronic lymphocytic leukemias, and myeloproliferative tumors, as well as nonhematological tumors, including tumors of the esophagus, breast, and central nervous system. Additionally, we explored the theranostic applications of CXCR4-targeting radioligands in tumors. Targeting CXCR4 using nuclear medicine shows promise as a method for tumor diagnosis, and further research is warranted to enhance its clinical applicability.

Who publishes imaging articles in non-imaging journals? A large sample data-mining study

OBJECTIVES

To assess the weight of imaging and imaging specialists (i.e., affiliated to a radiology/nuclear medicine department) in publications in non-imaging journals.

METHODS

All articles indexed in English on the Embase database between 1989 and 2019 were extracted. The number and affiliation of authors were determined. A naive Bayesian classifier algorithm was trained to classify abstracts as "imaging" or "non-imaging." The main outcome was the number and position of imaging specialists in the authorship of imaging articles published in non-imaging journals. Analyses per medical specialties and per journal impact factor (IF) were performed.

RESULTS

A total of 15,787,825 articles were included with 968,259 (6%) "imaging" articles. The proportion of imaging articles increased over time (+ 370%), quicker than the overall academic output. The proportion of imaging specialist among authors grew from 0.58% in 1989-1994 to 1.54% in 2015-2019. About 20% of imaging articles had ≥ 1 imaging specialist among authors. The proportion of imaging articles decreased with the IF (7.3% for IF 0-2.5 vs. 5.1% for IF > 10, p < 0.001), but the proportion of imaging specialist authors in imaging papers with ≥ 1 imaging specialist author increased with the IF (40% for IF 0-2.5, 53% for IF > 10, p < 0.001). There was significant variability across medical specialties.

CONCLUSIONS

The weight of imaging articles and imaging specialist among authors in non-imaging journals has increased over time but remains limited. Most of the authors of imaging publications are not imaging specialists. Imaging specialists among authors in imaging papers are associated with a greater IF.

KEY POINTS

• The proportion of imaging specialist authors in non-imaging journals, though small, has increased significantly. • Marked differences are observed according to medical specialties and the reputation/impact factor of the journal. • Collaboration between imaging specialists and non-specialists is associated with publication in higher impact journals.

161Tb-PSMA Unleashed: a Promising New Player in the Theranostics of Prostate Cancer

Radiotheranostics with 177Lu-PSMA have changed the treatment paradigm in patients with prostate cancer, becoming the new standard in certain settings. Terbium-161 (161Tb) has been recently investigated as a potential radionuclide for radiotheranostics in various types of cancer, including metastatic castration-resistant prostate cancer (mCRPC). The nuclear medicine team at King Hussein Cancer Center (KHCC) in Amman, Jordan, recently published the first-in-human SPECT/CT imaging results following a well-tolerated dose of 161Tb-PSMA radioligand therapy with no treatment-related adverse events, adding to the potential of radiotheranostics in prostate cancer. Two clinical trials for 161Tb-PSMA radioligand therapy in prostate cancer are currently underway and will provide valuable insights. This review will shed light on the expanding field of radiotheranostics in prostate cancer, which is not without challenges, and will discuss how the introduction of a new therapeutic option like 161Tb-PSMA may help to combat these challenges and build on the proven success of 177Lu-PSMA-based radiotheranostics for the benefit of prostate cancer patients worldwide.

Radiological study of a wastewater treatment plant associated with radioiodine therapy at a hospital in West Java, Indonesia

Nuclear Medicine (NM) services in Indonesia have rapidly developed due to the increasing number of patients, and this growth has been supported by standardized regulations in the field, including the management of solid waste generated. However, multiple reports indicate that licensing control doesn't regulate liquid waste disposal from patient excretions to protect personnel and the community from radiopharmaceutical exposure. One of the radiopharmaceuticals commonly used in NM and having the longest half-life among the radiopharmaceuticals used in NM is Iodine 131(I-131). Thus, this study used a high-purity germanium (HPGe) detector to measure Iodine-131 (I-131) activity in liquid waste from decay tanks, temporary collection channels, the hospital's wastewater treatment plant (WWTP) outlet, and six points around the Nuclear Medicine (NM) service and liquid waste treatment unit. Concentration measurements in three decay tanks were carried out sequentially every 12 hours for 3 days, corresponding to the therapy period. The results showed that the I-131 activity levels in the decay tanks and temporary collection channels, before being mixed with liquid waste from other units, were 95.9 x 106 ± 4.4 x 106 Bq/m³. At the point where the liquid waste from other units was mixed, the activity level decreased significantly to 47,2680±22,160 Bq/m³, which was below the clearance level of 107 Bq/m³. However, the recorded concentration exceeded the standard for environmental radioactivity at the hospital's Waste Water Treatment Plant (WWTP) outlet, namely 37,670 ± 2,040 Bq/m³. The measurement results for I-131 in the air in the open space for two nuclear buildings was above the standard at 1.3 ± 0.27 Bq/m³. According to the RESRAD simulation, based on the initial dose taken from the liquid waste treatment outlet point, the accumulation of doses and the risk of cancer among workers and the community decreased within 3 months after the maximum exposure.