Nuclear Medicine Procedures Research Articles

Research reactor model for isotope production based on the design of VVER-440 reactors

Abstract The following work is an attempt to develop a model research reactor based on VVER-440 technologies, primarily for the production of radioisotopes used in nuclear medicine procedures. The article describes the basic design features of the model 10 MW multipurpose VVR reactor, including the features of reactor fuel, core, and related structures. A comparative analysis of targets for maximizing 99Mo production is also presented.

Effective dose in medicine.

The International Commission on Radiological Protection (ICRP) developed effective dose as a quantity related to risk for occupational and public exposure. There was a need for a similar dose quantity linked to risk for making everyday decisions relating to medical procedures. Coefficients were developed to enable the calculation of doses to organs and tissues, and effective doses for procedures in nuclear medicine and radiology during the 1980s and 1990s. Effective dose has provided a valuable tool that is now used in the establishment of guidelines for patient referral and justification of procedures, choice of appropriate imaging techniques, and providing dose data on potential exposure of volunteers for research studies, all of which require the benefits from the procedure to be weighed against the risks. However, the approximations made in the derivation of effective dose are often forgotten, and the uncertainties in calculations of risks are discussed. An ICRP report on protection dose quantities has been prepared that provides more information on the application of effective dose, and concludes that effective dose can be used as an approximate measure of possible risk. A discussion of the way in which it should be used is given here, with applications for which it is considered suitable. Approaches to the evaluation of risk and methods for conveying information on risk are also discussed.

The quantification of PET-CT radiotracers to determine minimal scan time using quadratic formulation.

18F is the most extensively used radioisotope in current clinical practices of PET imaging. This selection is based on the several criteria of pure PET radioisotopes with an optimum half-life, and low positron energy that contributes to a smaller positron range. In addition to 18F, other radioisotopes such as 68Ga and 124I are currently gained much attention with the increase in interest in new PET tracers entering the clinical trials. Thisstudy aimstodeterminethe minimal scan time per bed position (Tmin) for the 124I and 68Gabased on the quantitative differences in PET imaging of 68Ga and 124I relative to 18F. The European Association of Nuclear Medicine (EANM) procedure guidelines version 2.0 for FDG-PET tumor imaging has adhered for this purpose. A NEMA2012/IEC2008 phantom was filled with tumor to background ratio of 10:1 with the activity concentration of 30kBq/ml ± 10 and 3kBq/ml ± 10% for each radioisotope. The phantom was scanned using different acquisition times per bed position (1, 5, 7, 10 and 15min) to determine the Tmin. The definition of Tmin was performed using an image coefficient of variations (COV) of 15%. Tmin obtained for 18F, 68Ga and 124I were 3.08, 3.24 and 32.93min, respectively. Quantitative analyses among 18F, 68Ga and 124I images were performed. Signal-to-noise ratio (SNR), contrast recovery coefficients (CRC), and visibility (VH) are the image quality parameters analysed in this study. Generally, 68Ga and 18F gave better image quality as compared to 124I for all the parameters studied. We have defined Tmin for 18F, 68Ga and 124I SPECT CT imaging based on NEMA2012/IEC2008 phantom imaging. Despite the long scanning time suggested by Tmin, improvement in the image quality is acquired especially for 124I. In clinical practice, the long acquisition time, nevertheless, may cause patient discomfort and motion artifact.

Using a ‘vector rotation’ technique and ‘parallel geometry’ utility to calculate the equivalent dose rate from a patient undergoing nuclear medicine procedures

A dose calculation for a person who has been in contact with a patient undergoing Nuclear medicine procedures can be performed by using Merged Phantom Tool (MPT). In this study, we are upgrading the MPT to help users easily merge phantoms at any axis and with any angle using the “vector rotation” technique. The segmented structure information of the contact’s phantom is also included in the calculation using the GEANT4 “parallel geometry” utility. The calculation is applied to a case of a male cancer patient lying on a bed who has used I-131, and a caregiver standing beside the patient. The equivalent dose to the thyroid of the caregiver is calculated at 0.3, 0.5, 0.8 and 1m away from the patient, as the caregiver is standing near the patient’s abdomen, chest and neck area. The results show that the dose to the thyroid of the contact greatly depends on his standing position and that there are clear differences between the results calculated with the point source and those calculated with the patient source. In summary, using activity distributions in the patient’s body as well as the right communication circumstance helps to calculate the optimal dose for people who have been in contact with patients.

A review of pediatric neuroendocrine tumors, their detection, and treatment by radioisotopes.

Neuroendocrine tumors (NETs) are rare in childhood. Neuroblastoma is the most common pediatric extracranial solid tumor, occurring >90% in children younger than 5 years of age. Pheochromocytoma and paraganglioma are rare NETs, causing hypertension in 0.5-2% of hypertensive children. Gastroenteropancreatic NETs can occur in children and are classified into carcinoids and pancreatic tumors. Nuclear medicine procedures have an essential role both in the diagnosis and treatment of NETs. Metaiodobenzylguanidine (MIBG) labeled with radioiodine has a well-established role in diagnosis as well as therapeutic management of the neuroblastoma group of diseases. During recent decades, establishing the abundant expression of somatostatin receptors by NETs first led to scintigraphy with somatostatin analogs (i.e. Tc/In-octreotide) and, later, with the emergence of positron-emitting labeled agents (i.e. Ga-DOTATATE/DOTATOC/DOTANOC) PET scans with significantly higher detection efficiency became available. Therapy with somatostatin analogs labeled with beta emitters such as Lu-177 and Y-90, known as peptide receptor radionuclide therapy, is a promising new option in the management of patients with inoperable or metastasized NETs. In this article, pediatric NETs are briefly reviewed and the role of radioactive agents in the detection and treatment of these tumors is discussed.

Dosimetry of tumor targeting imaging by convergent X-ray beam as compared with nuclear medicine

During decades nuclear medicine procedures, based on radiolabeled agents, have proved to be efficient for diseases diagnosis and treatment. Radiation emerging from patient is detected aimed at localizing radiotracer distribution that is further correlated with biochemical/metabolic physiological processes. However, a significant drawback associated with current nuclear medicine procedures implementing radionuclide infusion regards to the inherent absorbed dose as well as radiopharmaceuticals' production, storage and elimination from patient body, thus representing a risk at patient and public health level.In the recent years, alternative methods have been proposed to reduce/eliminate radionuclides in some nuclear medicine procedures. The combination of high atomic number nanoparticles infused within patient body with incident X-ray beam, like tumor targeting and treatment, appears as a potential alternative method capable of theranostics. The process is based on inducing X-ray fluorescence and secondary electrons emission in high atomic number nanoparticles by means of excitation with an external X-ray beam, avoiding employing radioactive substances.The present work reports on the dosimetry performance of both methods, comparing whenever the external convergent X-ray beam alternative may involve less or larger radiation dose levels, according to comparable signal/image quality during the procedure. To this aim, a simplified theoretical model is proposed and associated Monte Carlo simulations are performed in order to compare typical case of nuclear medicine imaging with potential performance of an innovative method, called OXIRIS (Orthovoltage X-ray Induced Radiation and Integrated System), based on convergent X-ray beam exciting high atomic number nanoparticles infused in patient.The obtained results support the proposed alternative method's feasibility, once demonstrated that patient absorbed dose levels are relative similar to those currently used by nuclear medicine procedures, whereas dose to targeted region (tumor) are significantly higher, which may be useful for treatment purposes.

National survey to set diagnostic reference levels in nuclear medicine single photon emission imaging in Croatia.

In order to introduce the concept of diagnostic reference levels (DRLs) in the national nuclear medicine practice a survey was proposed and completed through all nuclear medicine departments in Croatia. An additional aim was to increase the awareness of importance and full implementation of a comprehensive quality program that includes devices used in the nuclear medicine chain. Data were collected for more than 30 nuclear medicine single photon emission procedures. National DRLs (NDRLs) as administered activity and also as administered activity per unit mass were calculated in accordance to International Commission on Radiological Protection (ICRP) recommendations. Additionally, effective doses were estimated using conversion factors published by the ICRP. NDRLs for nuclear medicine single photon emission procedures were proposed. For procedures performed in only one department typical values were presented as reference. Effective doses related to applied radiopharmaceuticals were calculated to estimate radiation risk related to respective nuclear medicine procedure in more detail. This work presents results of the first national survey on DRLs of nuclear medicine single photon emission procedures and proposes reliable NDRLs that represent an actual status of nuclear medicine practice in Croatia. Results have motivated departments to introduce and set their own typical values to be used, as one of the tools, for further optimization process. One of the drawbacks of the DRL concept in nuclear medicine is the lack of the image quality parameters involved. For this reason, a quantity that considers both radiation protection and image quality should be introduced.

Global Impact of COVID-19 on Nuclear Medicine Departments: An International Survey in April 2020.

The coronavirus disease 2019 (COVID-19) pandemic has placed significant challenges on health-care systems worldwide, whether in the preparation, response, or recovery phase of the pandemic. This has been primarily managed by dramatically reducing in- and outpatient services for other diseases and implementing infection prevention and control measures. The impact of the pandemic on nuclear medicine departments and their services has not yet been established. The aim of this online survey was to evaluate the impact of COVID-19 on nuclear medicine departments. Methods: A web-based questionnaire, made available from April 16 to May 3, 2020, was designed to determine the impact of the pandemic on in- and outpatient nuclear medicine departments, including the number of procedures, employee health, availability of radiotracers and other essential supplies, and availability of personal protective equipment. The survey also inquired about operational aspects and types of facilities as well as other challenges. Results: A total of 434 responses from 72 countries were registered and analyzed. Respondents reported an average decline of 54% in diagnostic procedures. PET/CT scans decreased by an average of 36%, whereas sentinel lymph-node procedures decreased by 45%, lung scans by 56%, bone scans by 60%, myocardial studies by 66%, and thyroid studies by 67%. Of all participating centers, 81% performed radionuclide therapies, and they reported a reduction of 45% on average in the last 4 wk, ranging from over 76% in Latin America and South East Asia to 16% in South Korea and Singapore. Survey results showed that 52% of participating sites limited their 99mTc/99Mo generator purchases, and 12% of them temporarily cancelled orders. Insufficient supplies of essential materials (radioisotopes, generators, and kits) were reported, especially for 99mTc/99Mo generators and 131I, particularly in Africa, Asia, and Latin America. Conclusion: Both diagnostic and therapeutic nuclear medicine procedures declined precipitously, with countries worldwide being affected by the pandemic to a similar degree. Countries that were in the postpeak phase of the pandemic when they responded to the survey, such as South Korea and Singapore, reported a less pronounced impact on nuclear medicine services; however, the overall results of the survey showed that nuclear medicine services worldwide had been significantly impacted. In relation to staff health, 15% of respondents experienced COVID-19 infections within their own departments.

Current Applications for Nuclear Medicine Imaging in Pulmonary Disease.

Purpose of ReviewThe main goal of the article is to familiarize the reader with commonly and uncommonly used nuclear medicine procedures that can significantly contribute to improved patient care. The article presents examples of specific modality utilization in the chest including assessment of lung ventilation and perfusion, imaging options for broad range of infectious and inflammatory processes, and selected aspects of oncologic imaging. In addition, rapidly developing new techniques utilizing molecular imaging are discussed.Recent FindingsThe article describes nuclear medicine imaging modalities including gamma camera, SPECT, PET, and hybrid imaging (SPECT/CT, PET/CT, and PET/MR) in the context of established and emerging clinical applications. Areas of potential future development in nuclear medicine are discussed with emphasis on molecular imaging and implementation of new targeted tracers used in diagnostics and therapeutics (theranostics).SummaryNuclear medicine and molecular imaging provide many unique and novel options for the diagnosis and treatment of pulmonary diseases. This article reviews current applications for nuclear medicine and molecular imaging and selected future applications for radiopharmaceuticals and targeted molecular imaging techniques.

NCINM: organ dose calculator for patients undergoing nuclear medicine procedures

Nuclear medicine is the second largest source of medical radiation exposure to the general population after computed tomography imaging. Informed decisions regarding the use of nuclear medicine procedures require a better understanding of the magnitude of radiation dose and associated health risks. However, existing model-based organ dose estimation tools rely on simplified human anatomy models or commercial programs. Therefore, we developed a publicly-available dose calculation tool based on more sophisticated human anatomy models. We calculated a comprehensive library of photon and electron specific absorbed fractions (SAF) for multiple combinations of source and target regions within a series of pediatric and adult computational human phantoms matching the International Commission on Radiological Protection (ICRP)’s reference data, combined with a Monte Carlo radiation transport code. Then, we derived a library of S values from these SAFs and the nuclear decay data from ICRP Publication 107. Finally, we created a graphical user interface, named National Cancer Institute Dosimetry System for Nuclear Medicine (NCINM), to facilitate the dosimetry process. Approximately 13 million S values were derived from 2 million SAFs computed in this work. Comprehensive comparisons were conducted at different steps of the dosimetry chain with data available in software OLINDA/EXM 1.0 and IDAC 2.1. For instance, median ratios of photon self-absorption SAFs available from OLINDA/EXM 1.0 and IDAC 2.1 to those calculated in this study were 1.3 (interquartile range = 1.1–1.6) and 1.0 (interquartile range = 0.98–1.0), respectively. SAF differences between NCINM and OLINDA/EXM 1.0 were explained by the large inter-phantom anatomical variability. Our results illustrate the importance of realistic human anatomy models for use in dosimetry software. More phantoms and radionuclides, as well as a biokinetic module, will soon be added. Applications of the NCINM program include computation of absorbed doses for use in radiation epidemiologic studies and patient dose monitoring in nuclear medicine.

Global Issues of Radiopharmaceutical Access and Availability: A Nuclear Medicine Global Initiative Project.

The Nuclear Medicine Global Initiative was formed in 2012 by 13 international organizations to promote human health by advancing the field of nuclear medicine and molecular imaging by supporting the practice and application of nuclear medicine. The first project focused on standardization of administered activities in pediatric nuclear medicine and resulted in 2 articles. For its second project the Nuclear Medicine Global Initiative chose to explore issues impacting on access and availability of radiopharmaceuticals around the world. Methods: Information was obtained by survey responses from 35 countries on available radioisotopes, radiopharmaceuticals, and kits for diagnostic and therapeutic use. Issues impacting on access and availability of radiopharmaceuticals in individual countries were also identified. Results: Detailed information on radiopharmaceuticals used in each country, and sources of supply, was evaluated. Responses highlighted problems in access, particularly due to the reliance on a sole provider, regulatory issues, and reimbursement, as well as issues of facilities and workforce, particularly in low- and middle-income countries. Conclusion: Strategies to address access and availability of radiopharmaceuticals are outlined, to enable timely and equitable patient access to nuclear medicine procedures worldwide. In the face of disruptions to global supply chains by the coronavirus disease 2019 outbreak, renewed focus on ensuring a reliable supply of radiopharmaceuticals is a major priority for nuclear medicine practice globally.

Preliminary evaluation of the production of non-carrier added 111Ag as core of a therapeutic radiopharmaceutical in the framework of ISOLPHARM_Ag experiment

Research in the field of radiopharmaceuticals is increasingly promoted by the widespread and growing interest in applying nuclear medicine procedures in both disease diagnosis and treatment. The production of radionuclides of medical interest is however a challenging issue. Along with the conventional techniques other innovative approaches are being investigated and, among those, the ISOLPHARM project is being developed at INFN-LNL (Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali di Legnaro). Such technique foresees the employment of the SPES ISOL facility to produce isobarically pure Radioactive Ion Beams (RIBs), obtained thanks to electromagnetic mass separation and collected on appropriate substrates. The latter are successively recovered and dissolved, allowing thus the chemical separation and harvesting of the nuclides of interest, free from any isotopic contaminant. Although ISOLPHARM can be potentially employed for most of the routinely used medical radioisotopes, its innovation potential is better expressed considering its capability to provide carrier free unconventional nuclides, difficult to produce with state-of-art techniques, such as 111Ag, a β— emitter potentially interesting for therapeutic applications. Thus, in the framework of ISOLPHARM, INFN supported a two-years experiment, called ISOLPHARM_Ag, aimed at evaluating the feasibility of the production of a111Ag labelled radiopharmaceutical. The ISOL production yields are estimated by computing intensive Monte Carlo codes, that require an appropriate custom Information Technology infrastructure. The presented work is focused on the first part of the production chain including the capability to extract, ionize, and collect stable Ag beams with SPES technologies. MC calculations were used to estimate the expected 111Ag in-target yields, whereas experiments with stable Ag were performed to test the ionization, transport and collection of Ag beams.

The Neuroendocrine Neoplasms of the Digestive Tract: Diagnosis, Treatment and Nutrition.

Nuroendocrine neoplasms (NENs) are a group of rare neoplasms originating from dispersed neuroendocrine cells, mainly of the digestive and respiratory tract, showing characteristic histology and immunoprofile contributing to classification of NENs. Some NENs have the ability to produce biogenic amines and peptide hormones, which may be associated with clinical syndromes like, e.g., the carcinoid syndrome caused by unmetabolized overproduced serotonin, hypoglycemic syndrome in case of insulinoma, or Zollinger-Ellison syndrome accompanying gastrinoma. Diagnostics for these include ultrasound with endoscopic ultrasound (EUS), computed tomography (CT), magnetic resonance imaging (MRI), and positron-emission tomography/computed tomography (PET/CT). Different nuclear medicine procedures can also be used, like somatostatin analogues scintigraphy (SRS) and 68Ga-Dota-Peptide PET/CT, as well as biochemical methods to determine the level of general neuroendocrine markers, such as chromogranin A (CgA), 5-hydroxyindolacetic acid (5-HIAA), synaptopfysin and cell type-specific peptide hormones, and neurotransmitters like gastrin, insulin, serotonin, and histamine. NENs influence the whole organism by modulating metabolism. The treatment options for neuroendocrine neoplasms include surgery, somatostatin analogue therapy, radionuclide therapy, chemotherapy, molecular targeted therapies, alpha-interferon therapy, and inhibitors of serotonin production. In the case of hypersensitivity to biogenic amines, a diet that limits the main sources of amines should be used. The symptoms are usually connected with histamine, tyramine and putrescine. Exogenic sources of histamine are products that take a long time to mature and ferment. Patients with a genetic insufficiency of the diamine oxidase enzyme (DAO), and those that take medicine belonging to the group of monoamine oxidases (MAO), are particularly susceptible to the negative effects of amines. Diet plays an important role in the initiation, promotion, and progression of cancers. As a result of the illness, the consumption of some nutrients can be reduced, leading to nutritional deficiencies and resulting in malnutrition. Changes in metabolism may lead to cachexia in some patients suffering from NENs. The aim of this narrative review was to advance the knowledge in this area, and to determine possibilities related to dietary support. The authors also paid attention to role of biogenic amines in the treatment of patients with NENs. We can use this information to better understand nutritional issues faced by patients with gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs), and to help inform the development of screening tools and clinical practice guidelines.

In Silico Modelling in the Development of Novel Radiolabelled Peptide Probes.

This review describes the usefulness of in silico design approaches in the design of new radiopharmaceuticals, especially peptide-based radiotracers (including peptidomimetics). Although not part of the standard arsenal utilized during radiopharmaceutical design, the use of in silico strategies is steadily increasing in the field of radiochemistry as it contributes to a more rational and scientific approach. The development of new peptide-based radiopharmaceuticals as well as a short introduction to suitable computational approaches are provided in this review. The first section comprises a concise overview of the three most useful computeraided drug design strategies used, namely i) a Ligand-based Approach (LBDD) using pharmacophore modelling, ii) a Structure-based Design Approach (SBDD) using molecular docking strategies and iii) Absorption-Distribution-Metabolism-Excretion-Toxicity (ADMET) predictions. The second section summarizes the challenges connected to these computer-aided techniques and discusses successful applications of in silico radiopharmaceutical design in peptide-based radiopharmaceutical development, thereby improving the clinical procedure in Nuclear Medicine. Finally, the advances and future potential of in silico modelling as a design strategy is highlighted.

Invited Commentary: Changing Landscape of Imaging in Recurrent Prostate Cancer.

Invited Commentary: Changing Landscape of Imaging in Recurrent Prostate Cancer.

Nuclear medicine and molecular imaging advances in the 21st century.

Currently, Nuclear Medicine has a clearly defined role in clinical practice due to its usefulness in many medical disciplines. It provides relevant diagnostic and therapeutic options leading to patients' healthcare and quality of life improvement. During the first two decades of the 21stt century, the number of Nuclear Medicine procedures increased considerably.Clinical and research advances in Nuclear Medicine and Molecular Imaging have been based on developments in radiopharmaceuticals and equipment, namely, the introduction of multimodality imaging. In addition, new therapeutic applications of radiopharmaceuticals, mainly in oncology, are underway.This review will focus on radiopharmaceuticals for positron emission tomography (PET), in particular, those labeled with Fluorine-18 and Gallium-68. Multimodality as a key player in clinical practice led to the development of new detector technology and combined efforts to improve resolution. The concept of dual probe (a single molecule labeled with a radionuclide for single photon emission computed tomography)/positron emission tomography and a light emitter for optical imaging) is gaining increasing acceptance, especially in minimally invasive radioguided surgery. The expansion of theranostics, using the same molecule for diagnosis (γ or positron emitter) and therapy (β minus or α emitter) is reshaping personalized medicine.Upcoming research and development efforts will lead to an even wider array of indications for Nuclear Medicine both in diagnosis and treatment.

Guide for Nuclear Medicine Applications During the COVID-19 Outbreak.

A viral pneumonia rapidly spread from Wuhan, China to all countries in late 2019. In February 2020, WHO named as Coronavirus Disease 2019 (COVID-19) and declared the pandemic on March 11, 2020. To prevent the spread of COVID-19, Ministry of Health of Republic of Turkey and international institutions have published documents defining hygiene rules. After the lung computerized tomography (CT) findings which are important in the diagnosis of COVID-19 are described, protection measures against infection were defined in radiology departments. There is no publication involving protection measures for diagnostic and therapeutic procedures in nuclear medicine (NM) (appointment, patient acceptance, imaging and treatment procedures, disinfection etc). There are two reports on CT findings suggesting COVID-19 in 18F--fluorodeoxyglucose positron emission tomography/CT scan. These lung findings detected in hybrid images will be helpful in the early diagnosis of pulmonary involvement. Infected cases may be asymptomatic and can unintentionally disseminate the virus to surrounding people. This advisory guide has been prepared to avoid infection risk in NM clinics. During the COVID-19 outbreak, staff must use proper personal protective equipment and patients should be evaluated as the elective case according to clinical status. A questionnaire should be made for COVID-19. In cancer cases requiring urgent treatment, radionuclide treatment (RNT) should be planned according to the COVID-19 test result. If the result is negative, RNT can be applied; but if not or if the symptoms are present, RNT must be postponed. Following imaging procedures, scanners and room surfaces should be cleaned by personnel with proper disinfection training.

Animal Models for the Evaluation of Theranostic Radiopharmaceuticals.

Theranostic is a new field of medicine that combines diagnosis and patient- specific targeted treatment. In the theranostic approach, it is aimed to detect diseased cells by using targeted molecules using disease-specific biological pathways and then destroy them by cellular irradiation without damaging other tissues. Diagnostic tests guide the use of specific therapeutic agents by demonstrating the presence of the receptor/molecule on the target tissue. As the therapeutic agent is administered to patients who have a positive diagnostic test, the efficacy of treatment in these patients is largely guaranteed. As therapeutic efficacy can be predicted by therapeutic agents, it is also possible to monitor the response to treatment. Many diagnostic and therapeutic procedures in nuclear medicine are classified as theranostic. 131I treatment and scintigraphy are the best examples of the theranostic application. Likewise, 177Lu / 90Y octreotate for neuroendocrine tumors, 177Lu PSMA for metastatic or treatment-resistant prostate cancer, 90Y SIRT for metastatic liver cancer, and 223Ra for bone metastasis of prostate cancer are widely used. Moreover, nanoparticles are one of the most rapidly developing subjects of theranostics. Diagnostic and therapeutic agents that show fluorescent, ultrasonic, magnetic, radioactive, contrast, pharmacological drug or antibody properties are loaded into the nanoparticle to provide theranostic use. This article reviewed general aspects of preclinical models for theranostic research, and presented examples from the literature. To achieve successful results in rapidly accelerating personalized treatment research of today, the first step is to conduct appropriate preclinical studies.

From Theranostics to Immunotheranostics: the Concept.

Immunotheranostics will be an important development in the future of nuclear medicine and medical oncology. It describes the synergy of theranostic procedures in nuclear medicine and immune oncology (IO) treatment. In brief, it takes advantage of molecular imaging and subsequent targeted modulation of the-in most cases immunosuppressive-tumor microenvironment (TME) by diagnostic and therapeutic radioisotopes. This is of high importance since only a fraction of patients receiving IO is currently being cured by this exciting therapy option. We therefore envision the concept of immunotheranostics as a powerful mean to augment the success of IO treatment in the future and thus the urgent need to further develop the interaction and joint action of nuclear medicine and medical oncology for substantially improved therapy outcome for cancer patients.

Patient Exposure from Radiologic and Nuclear Medicine Procedures in the United States: Procedure Volume and Effective Dose for the Period 2006-2016.

Background Comprehensive assessments of the frequency and associated doses from radiologic and nuclear medicine procedures are rarely conducted. The use of these procedures and the population-based radiation dose increased remarkably from 1980 to 2006. Purpose To determine the change in per capita radiation exposure in the United States from 2006 to 2016. Materials and Methods The U.S. National Council on Radiation Protection and Measurements conducted a retrospective assessment for 2016 and compared the results to previously published data for the year 2006. Effective dose values for procedures were obtained from the literature, and frequency data were obtained from commercial, governmental, and professional society data. Results In the United States in 2006, an estimated 377 million diagnostic and interventional radiologic examinations were performed. This value remained essentially the same for 2016 even though the U.S. population had increased by about 24 million people. The number of CT scans performed increased from 67 million to 84 million, but the number of other procedures (eg, diagnostic fluoroscopy) and nuclear medicine procedures decreased from 17 million to 13.5 million. The number of dental radiographic and dental CT examinations performed was estimated to be about 320 million in 2016. Using the tissue-weighting factors from Publication 60 of the International Commission on Radiological Protection, the U.S. annual individual (per capita) effective dose from diagnostic and interventional medical procedures was estimated to have been 2.9 mSv in 2006 and 2.3 mSv in 2016, with the collective doses being 885 000 and 755 000 person-sievert, respectively. Conclusion The trend from 1980 to 2006 of increasing dose from medical radiation has reversed. Estimated 2016 total collective effective dose and radiation dose per capita dose are lower than in 2006. © RSNA, 2020 See also the editorial by Einstein in this issue.