SNMMI Clinical Trials Network Research Series for Technologists: An Introduction to Conducting Theranostic Clinical Trials.

This article is intended to introduce nuclear medicine technologists (NMTs) to the nuances of radiopharmaceutical therapy clinical trials. Here, we outline the potential roles and responsibilities of the NMT in clinical trials and provide context on different aspects of radionuclide therapy. The regulatory process involving investigational therapeutic radiopharmaceuticals is seldom taught to NMT students, nor is it included in the entry-level nuclear medicine certification examinations. Often, NMTs must spend significant time preparing for therapeutic clinical trials on their own, using multiple academic sources, seeking advice from various health care professionals, and reviewing numerous trial-specific manuals to recognize the detailed requirements. The emergence of theranostics has spurred an increase in the development of therapeutic radiopharmaceuticals. Investigators with a robust nuclear medicine background are required to help develop successful therapeutic clinical trials, and well-informed NMTs are crucial to the success of such trials. This article follows a series of previous publications from the Society of Nuclear Medicine and Molecular Imaging Clinical Trials Network research series for technologists and is intended to guide the investigational radiopharmaceutical landscape.

Radiolabeled Probes from Derivatives of Natural Compounds Used in Nuclear Medicine.

Natural compounds are important precursors for the synthesis of new drugs. The development of novel molecules that are useful for various diseases is the main goal of researchers, especially for the diagnosis and treatment of many diseases. Some pathologies need to be treated with radiopharmaceuticals, and, for this reason, radiopharmaceuticals that use the radiolabeling of natural derivates molecules are arousing more and more interest. Radiopharmaceuticals can be used for both diagnostic and therapeutic purposes depending on the radionuclide. ß+- and gamma-emitting radionuclides are used for diagnostic use for PET or SPECT imaging techniques, while α- and ß--emitting radionuclides are used for in metabolic radiotherapy. Based on these assumptions, the purpose of this review is to highlight the studies carried out in the last ten years, to search for potentially useful radiopharmaceuticals for nuclear medicine that use molecules of natural origin as lead structures. In this context, the main radiolabeled compounds containing natural products as scaffolds are analyzed, in particular curcumin, stilbene, chalcone, and benzofuran. Studies on structural and chemical modifications are emphasized in order to obtain a collection of potential radiopharmaceuticals that exploit the biological properties of molecules of natural origin. The radionuclides used to label these compounds are 68Ga, 44Sc, 18F, 64Cu, 99mTc, and 125I for diagnostic imaging.

Indications for nuclear medicine imaging in prostate cancer.

Nuclear medicine imaging for prostate cancer has advanced significantly over the past decade. A survey is presented in this review. PSMA-PET/CT is a new highly accurate method that has been introduced, but bone scans and bone-PET continue to be widely applied. PSMA-PET/CT still lacks sufficient patient outcome data to be recommended for treatment allocation when used for primary staging. However, the literature and clinical guidelines support its use at the stage of biochemical recurrence. In Denmark, the use of nuclear medicine examinations for prostate cancer aligns with clinical guideline recommendations.

Assessment of foetal dose and occupational exposure for pregnant workers in nuclear medicine using the Taiwanese pregnancy phantom.

For pregnant workers in nuclear medicine, radiation doses can pose a risk to their foetus. However, foetal radiation doses cannot be measured directly. In this study, a method of estimating foetal radiation doses was developed through simulations and measurements of phantoms of pregnant women in the three trimesters. The uterus and abdominal surface doses for monoenergetic photons (137Cs) and medical diagnostic X-rays were measured, and uterine dose conversion coefficients (UDCCs) were calculated. The accuracy of the UDCC estimates were validated for measurements from thermoluminescent dosemeter (TLD) chips and TLD badges on the abdomen or chest. The foetal effective dose could be estimated using TLD chips and TLD badges on the abdomen or chest, or through literature estimation method. The proposed method can be used to easily and accurately estimate foetal effective doses from chest-worn TLD badges, ensuring accurate estimation in the early stage of pregnancy when a worker may not yet be wearing an abdominal badge. A flowchart for applying the UDCC method to approximate a foetal dose is also provided to ensure that total doses remain below the maximum of 1 mSv recommended in the International Commission on Radiological Protection 103 guidelines.

Evaluation of patients' radiation doses and establishment of institutional diagnostic reference levels in nuclear medicine in Oman.

This study aimed to develop diagnostic reference levels (DRLs) in Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) and Positron Emission Tomography/Computed Tomography (PET/CT) imaging for the most frequent SPECT/CT and PET/CT examinations performed at our institution. A total of 1134 adult patients, who have undergone SPECT/CT and PET/CT scanning over a period of 4 years (2018-2021), were included. The scans consisted of 401 PET/CT and 733 SPECT/CT scans. The CT dosimetry data [CT-dose-index (CTDIvol), dose-length-product (DLP)] and administered activities were collected. The DRLs were calculated for CTDIvol, DLP and administrated activity. The estimated DRLs are given as [median CTDIvol (mGy):median DLP (mGy.cm):median administrated activity (MBq)]: whole body PET/CT: 1.88:175:259; brain PET/CT: 12.9:300:239; cardiac PET/CT: 1.34:32:368; bone SPECT/CT: 2.68:116:763; MPI SPECT/CT (stress-rest): 1.49:52:751-721; parathyroid SPECT/CT: 3.1:126:779; thyroid uptake SPECT: 3.52:147:195; thyroid post-ablation SPECT/CT: 3.85:160:NA. The derived DRLs have allowed careful monitoring of doses delivered to patients and could act as a trigger to investigate doses that systematically exceeds the derived DRLs.

Mechanisms of inclusion of thallium-201 into Prussian blue nanoparticles for nuclear medicine applications.

Prussian blue is known for its high affinity for thallium and other univalent metal cations and has been used as a treatment for radiocaesium and thallium/radiothallium poisoning. While Prussian blue nanoparticles (PBNPs) show potential for binding radioactive thallium for further use in nuclear medicine applications, the inclusion mechanism remains elusive. Understanding the interaction between PBNPs and 201Tl is essential for identifying the physicochemical and radiochemical properties required for optimal in vivo performance. In this work, we evaluated the binding mechanism between Tl and PBNPs with different coatings and core shapes. Combining PBNPs with [201Tl] thallium(I) chloride provided high radiolabelling yields and radiochemical stabilities under physiological conditions. Comprehensive characterisation by different X-ray techniques confirmed that Tl ions are located in the interstitial sites within the crystal structure, maintaining the integrity of the iron (Fe) 4p electronic distribution and inducing local modifications in the nearby C-N ligands. Additionally, this inclusion does not impact the core or the shell of the nanoparticles but does alter their ionic composition. The PB ionic network undergoes significant changes, with a substantial drop in K+ content, confirming that Tl+ ions replace K+ and occupy additional spaces within the crystal structure. These results open new opportunities in nuclear medicine applications with 201Tl-PBNPs where the size, shape and composition of the particles can be specifically tuned depending on the desired biological properties without affecting the radiochemical performance as a vehicle for 201Tl.

Nuclear medicine imaging modalities to detect incidentalomas and their impact on patient management: a systematic review.

PURPOSE: This systematic review aims to investigate the role of nuclear imaging techniques in detecting incidentalomas and their impact on patient management. METHODS: Following PRISMA guidelines, a comprehensive literature search was conducted from February to May 2022. Studies in English involving patients undergoing nuclear medicine studies with incidental tumor findings were included. Data on imaging modalities, incidentaloma characteristics, management changes, and follow-up were extracted and analyzed. RESULTS: Ninety-two studies involving 64.884 patients were included. Incidentalomas were detected in 611 cases (0.9%), with thyroid being the most common site. PET/CT with FDG and choline tracers showed the highest incidentaloma detection rates. Detection of incidentalomas led to a change in therapeutic strategy in 59% of cases. Various radiotracers demonstrated high sensitivity for incidentaloma detection, particularly in neuroendocrine tumors and prostate cancer. CONCLUSION: Nuclear imaging techniques play a crucial role in detecting incidentalomas, leading to significant changes in patient management. The high sensitivity of these modalities highlights their potential in routine oncology follow-up protocols. Future directions may include enhancing spatial resolution and promoting theranostic approaches for improved patient care.

[Nuclear medicine approaches in the diagnosis and treatment of neuroendocrine neoplasms]. / Nuklearmedizinische Ansätze in Diagnostik und Therapie neuroendokriner Neoplasien.

Despite, or perhaps because of the rarity of neuroendocrine neoplasms, the diagnosis and treatment of these malignancies is of particular importance. Nuclear medicine can make an important contribution to this challenge. It offers the most sensitive and specific imaging of these tumor entities and can be helpful in treatment due to the radiotherapeutic drugs that have recently been approved. This theragnostic (fusion of therapeutic and diagnostic) concept is based on the frequent overexpression of somatostatin receptors on neuroendocrine tumor cells.Using diagnostic and therapeutic pharmaceuticals based on analogues from somatostatin, most applications from the nuclear medicine are successful, an additional therapeutic method is SIRT, also known as TARE, in which the hypervascularization of NEN-metastases is used as a therapeutic target.

The Rebirth of Radioimmunotherapy of Non-Hodgkin Lymphoma: The Phoenix of Nuclear Medicine?

In Greek mythology, The Phoenix is an immortal bird that dies, but then achieves new life by rising from the ashes of its predecessor. Radioimmunotherapy (RIT) of B-cell Non-Hodgkin lymphoma (NHL) is a field which once began to fly high-with FDA approval of the anti-CD20 RITs Zevalin® and Bexxar® in 2002 and 2003 respectively, as safe and effective therapies of NHL. However, despite their therapeutic efficacy, Bexxar® was withdrawn from the market by the manufacturer in 2014 due to limited commercial demand and Zevalin® has had very limited to no availability of late. I-131 rituximab is used to a limited extent in Australia, India and other countries, as well. But has RIT of NHL been (perhaps prematurely) left for dead by many? Given the current great clinical and commercial interest in radiopharmaceutical therapies of cancer, notably PSMA and SSTR targeting agents in prostate and neuroendocrine cancers, can radioimmunotherapy of NHL-like the mythical Phoenix-now rise from its ashes in an even better form to fly higher, faster, farther and longer than before?

Technostress in Nuclear Medicine: A Qualitative Study of Causes, Mitigators, and Resolution Levels.

BACKGROUND: In contemporary healthcare, information and communication technology enables specialized treatment and efficient information sharing. However, it also causes stress and frustration, so-called technostress, among healthcare staff. PURPOSE: To investigate the day-to-day occurrence of technostress, we ask the research question: What causes the stressful situations with technology, how are they mitigated, and to what extent are they resolved? METHOD: We interviewed 15 healthcare providers in the department of nuclear medicine at a Danish hospital about their experiences with technology-induced stress in their daily work. RESULTS: The interviewees described 185 stressful situations with technology, mostly technology indispensable to their work. The two most frequent causes of stressful situations are system performance (46%) and technology-related organizational procedures (18%). To mitigate the situations, the most frequent strategies are accommodating (51%), consulting others for help (18%), and repeating previous task steps (13%). The mitigation strategies indicate that the stressful situations involve adapting work practices to the technology to a much larger extent than succeeding in adapting the technology to the work. Regarding the level of resolution, as much as 66% of the stressful situations are merely solved for now, that is, the concrete situation is resolved but the underlying issue remains unsolved. The underlying issue is resolved in only 10% of the situations, thereby indicating that the vast majority of the stressful situations are likely to recur later. CONCLUSION: The staff at the studied hospital department repeatedly experience stressful situations with the technology they rely on in their work. This technostress is an extra stressor on top of those induced by the staff's responsibility for providing quality patient treatment. At the individual level, technostress leads to frustration and possibly burnout; at the organizational level, it calls for preventive action.

Combining Nuclear Medicine With Other Modalities: Future Prospect for Multimodality Imaging.

This meeting report summarizes a consultants meeting that was held at International Atomic Energy Agency Headquarters, Vienna, in July 2022 to provide an update on the development of multimodality imaging by combining nuclear medicine imaging agents with other nonradioactive molecular probes and/or biomedical imaging techniques.

Actinium-225 as an example for monitoring of internal exposure of occupational intakes of radionuclides in face of new nuclear-medical applications for short-lived alpha emitting particles.

Monitoring of internal exposure to short-lived alpha-emitting radionuclides such as actinium-225 (225Ac), which are becoming increasingly important in nuclear medicine, plays an important role in the radiation protection of occupationally exposed persons. After having tested gamma spectrometry, liquid scintillation counting and alpha spectrometry for monitoring of internal exposure, the focus of the present study was on solid phase extraction of 225Ac from urine in combination with alpha spectrometry. The development of the method was based on recent findings from the literature on this topic. The method was used in a pilot phase to monitor internal exposure of four workers who were directly or indirectly involved in the manufacture and/or use of 225Ac. The monitoring protocol allowed a relatively short 24-hour urine sample analysis with excellent recovery of the internal standard, but it did not allow for a detection limit of less than 1 mBq nor a sufficient yield of 225Ac. Based on these results it is concluded that an in vitro excretion analysis alone is not appropriate for monitoring internal exposure to 225Ac. Instead, different radiation monitoring techniques have to be combined to ensure the radiation protection of employees.

Nuclear medicine technologists practice impacted by AI denoising applications in PET/CT images.

PURPOSE: Artificial intelligence (AI) in positron emission tomography/computed tomography (PET/CT) can be used to improve image quality when it is useful to reduce the injected activity or the acquisition time. Particular attention must be paid to ensure that users adopt this technological innovation when outcomes can be improved by its use. The aim of this study was to identify the aspects that need to be analysed and discussed to implement an AI denoising PET/CT algorithm in clinical practice, based on the representations of Nuclear Medicine Technologists (NMT) from Western-Switzerland, highlighting the barriers and facilitators associated. METHODS: Two focus groups were organised in June and September 2023, involving ten voluntary participants recruited from all types of medical imaging departments, forming a diverse sample of NMT. The interview guide followed the first stage of the revised model of Ottawa of Research Use. A content analysis was performed following the three-stage approach described by Wanlin. Ethics cleared the study. RESULTS: Clinical practice, workload, knowledge and resources were de 4 themes identified as necessary to be thought before implementing an AI denoising PET/CT algorithm by ten NMT participants (aged 31-60), not familiar with this AI tool. The main barriers to implement this algorithm included workflow challenges, resistance from professionals and lack of education; while the main facilitators were explanations and the availability of support to ask questions such as a "local champion". CONCLUSION: To implement a denoising algorithm in PET/CT, several aspects of clinical practice need to be thought to reduce the barriers to its implementation such as the procedures, the workload and the available resources. Participants emphasised also the importance of clear explanations, education, and support for successful implementation. IMPLICATIONS FOR PRACTICE: To facilitate the implementation of AI tools in clinical practice, it is important to identify the barriers and propose strategies that can mitigate it.