Earticle

Background: The radiation safety regulation system, characterized by its critical and domestically tailored features, encountered unexpected challenges due to coronavirus disease 2019 (COVID-19). Accordingly, each country implemented diverse measures to ensure the continuous efficacy of its regulatory system. This study investigates the responses of five institutions concerning radiation safety, collecting data aiming to enhance preparedness through systematic procedure. Materials and Methods: The data were extracted from official documents or websites of respective regulatory bodies (RBs) that discussed their responses to the radiation safety regulation system from COVID-19. From this data, it was observed that each country responded uniquely based on its specific conditions. Results and Discussion: Due to the repercussions of COVID-19, the regulatory system faced challenges, particularly regarding on-site inspections. In response, many countries published COVID-19 annual reports, with a few set up dedicated websites addressing its impact on the radiation regulatory frameworks. This data observed the distinct and situation-specific approaches adopted by each country in response to the pandemic. Notably, several nations introduced digital technologies into their regulations, including remote systems and online methods, while also customizing their regulatory systems according to respective circumstances. Conclusion: A variety of responses from the national RB regarding the radiation safety regulation system after the outbreak of COVID-19 highlight the importance of crisis preparedness and indicate that the current regulatory system could be enhanced.

Diffusing alpha-emitters radiation therapy (DaRT) represents a groundbreaking development in cancer therapy, offering a solution to the limitations of conventional radiation therapy. By deploying 224Ra embedded seeds, DaRT achieves targeted delivery of high-dose alpha particles directly to tumor sites, showing considerable efficacy in tumor control and minimal damage to adjacent healthy tissues. This comprehensive review analyzes the published literature regarding mechanisms, seed production, dose calculation, measurement, and biological experiments related to DaRT. It includes in-depth discussions on mathematical models, Monte Carlo simulations for dose distribution, real-time in vivo dosimetry developments, and biological experiments both in vitro and in vivo. Clinical trial outcomes are also examined to evaluate the therapy’s effectiveness in various cancer types. DaRT utilizes 224Ra-labeled seeds, using the decay chain of 224Ra to deliver alpha particles effectively within a tumor. Several asymptotic diffusionleakage models were developed to calculate the alpha dose distribution of DaRT. In vivo dosimetry techniques have been developed for real-time monitoring. Biological experiments demonstrated the cytotoxic effects of DaRT across various cancer cells, with varying radiosensitivity. Additionally, the enhanced effects of combined therapy with chemotherapy and immunotherapy were suggested by many in vivo studies. Clinical trials have shown high complete response rate in squamous cell carcinoma, with minimal side effects, suggesting DaRT’s feasibility and safety. DaRT emerges as a highly localized cancer treatment method with minimal side effects compared to traditional radiation therapy. It directly ablates tumors and potentially enhances immune responses, indicating a significant advance in cancer therapy. Future research and ongoing clinical trials will further elucidate its efficacy across different cancer types and in combination with other treatments.

Background: Radiodiagnosis is widely performed in medical institutions. All medical professionals, including nurses, are at risk of radiation exposure. This study developed an educational application for radiation medical professionals to visualize the distribution of scattered radiation using augmented reality. Materials and Methods: A Monte Carlo simulation code was used to simulate mobile chest and abdominal radiography. The calculation results were incorporated into an augmented reality application. The results of the Monte Carlo calculations were validated by comparing them with radiation measurements. An augmented reality application for tablet devices was developed in Unity that visualizes the scattered radiation dose. Results and Discussion: The application was developed by visualizing the distribution of scattered radiation in mobile radiography in augmented reality in three-dimensional real space. The calculation results were validated, and the error between the displayed radiation dose values and the measured radiation dose values was generally less than 10%. Conclusion: The developed application allows users to overlay quantitative values of imperceptible radiation exposure doses onto any real-world environment. This enables users to intuitively understand the relationship between the distance from a radiation source and the received dose, thereby contributing to a better understanding of radiation protection in clinical settings.

Background: Practices involving radionuclides at levels below the International Atomic Energy Agency (IAEA) generic exemptions are exempt from regulation without further consideration. Practices involving radionuclides at levels above those generic exemptions may also be exempt from regulation if they meet certain conditions. These are known as specific exemptions, and each country has established its own specific exemption criteria based on the conditions set out in the IAEA General Safety Requirements (GSR) Part 3. Those conditions relate to the physical or chemical form of the radioactive material as well as to its use or the means of its disposal. Materials and Methods: The specific exemption criteria of eight countries (i.e. , the United States of America [US], Japan, France, China, Australia, Canada, the United Kingdom of Great Britain and Northern Ireland [UK], and Germany) were analyzed. Their similarities and differences as compared with the specific exemption criteria of the Republic of Korea (ROK) were analyzed, and suggestions for revision of the Korean regulations were formulated. Results and Discussion: Each country’s specific exemption criteria are defined based mostly on the IAEA criteria but tailored to its domestic circumstances. The nine countries with their specific exemption criteria can be broadly categorized into three groups: nuclide-specific exemptions for specific products (the ROK and the US), common criteria for all nuclides without specification of particular products (Japan, France, and China), and both specific and common criteria (Australia, Canada, the UK, and Germany). Conclusion: The specific exemption criteria of the different countries examined in this study could be helpful in reviewing the ROK’s specific exemption criteria. Development of common criteria alongside specific criteria for products requiring special attention may be a good way to determine whether new consumer products containing radioisotopes should be regulated.

Background: Computed tomography (CT) scans in the Republic of Korea have spiked, reaching approximately 9 million examinations annually in 2017. CT provides significant medical benefits, but radiation exposure remains a concern. This study aims to analyze CT scans in Korea, as a basis study for radiation safety management. Materials and Methods: The raw data of total CT scans was obtained from the Health Insurance Review & Assessment Service and analyzed by CT scan type, patients’ age and sex, and medical facility type. CT scans trends were analyzed considering the disease incidence. Results and Discussion: In 2017, CT scans accounted for 8,977,300. Usage per capita was 0.18 in males and 0.17 in females. CT scans increased with age until the 50- to 59-year-old groups, then decreased. CT scans were high in abdominal/pelvic (35%), chest (26%), and head (22%) regions due to higher disease rates. Head CT was most frequently used for infants and children. Abdominal/pelvic, chest, and spine CT were more frequent for older groups. The CT scans in the upper and lower extremities was high in child and juvenile groups. Chest and abdominal/ pelvic CTs were higher in males, whereas spine, whole spine, and CT densitometry were higher in females. The proportion of CT scans of tertiary and general hospitals, hospitals, and clinics accounted for ≥80%, 13%, and 5%, respectively. Abdomen/pelvis, chest, and head/ neck CTs were mostly conducted in tertiary and general hospitals, spine CT in hospitals and clinics, extremity CT in hospitals, and CT densitometry in clinics. Conclusion: The trend of CT scans varied based on the incidence rate for each patient’s sex and age, and serious illness diagnosis by medical facility type. The results of this study provide data and guidance for evaluating the radiation exposure of the Korean population by CT and developing management policies for medical radiation safety.