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Background: The situation in which radiation emerges uncontrollably is referred to as a radiation accident. Radiation accidents constitute emergencies that can have severe impacts on public health. Therefore, it is of critical importance for hospitals providing healthcare services to be adequately prepared for such incidents. Materials and Methods: This study aims to compare the hospital management protocols for radiation accidents in Türkiye and Japan using the strengths, weaknesses, opportunities, threats (SWOT) analysis method. As a country that has experienced a radiation accident, Japan’s postincident developments are compared with Türkiye’s current situation. The study first examines the radiation safety regulations, healthcare policies, and hospital management strategies of both countries. While Türkiye has established general protocols under the Hospital Disaster and Emergency Plan (HAP) and for Chemical, Biological, Radiological, and Nuclear (CBRN) incidents, Japan has enhanced its crisis management and emergency response systems following the 2011 Fukushima Nuclear Accident. Within the framework of the SWOT analysis, the strengths and weaknesses of both countries, potential threats, and opportunities for improvement are analyzed in detail. Results and Discussion: This study highlights how Türkiye can benefit from Japan’s crisis management experience to enhance its preparedness for radiation accidents. The analysis reveals that Türkiye has significant shortcomings, particularly in training, drills, and hospital infrastructure. However, its investments in nuclear energy provide opportunities for development through international collaborations. On the other hand, although Japan possesses advanced radiation monitoring systems and extensive experience, it remains under constant threat due to its high concentration of nuclear power plants and exposure to natural disasters. Conclusion: To prevent radiation accidents, it is recommended to develop a hospital management model based on international standards. Additionally, effective intervention strategies should be formulated through the collaborative decision-making of hospital administrators, healthcare professionals, and policymakers to ensure a comprehensive response to radiation accidents.

Background: This study aims to analyze the individual laws regulating radiation risks in South Korea in order to understand the legal framework for radiation risk regulation and to propose improvements necessary for effective radiation risk regulation. Materials and Methods: This study is qualitative in nature. Expert consultations were conducted, and current laws related to radiation risk regulation were identified through the legal information center’s search engine. Previous studies on radiation risk regulation were also reviewed. First, a total of 31 individual laws related to radiation risk were identified. Second, the objectives of each law, the scope of radiation risk regulation, and the responsible administrative departments were organized. Third, the structure of the current legal framework for radiation risk regulation was organized. Results and Discussion: The legal framework for regulating radiation risks in South Korea appears to be classified into two categories. One for regulating the risks associated with nuclear power generation and another for regulating radiation risks unrelated to nuclear power plants. Although the Nuclear Safety Act is not formally classified as a fundamental law, it exhibits characteristics typically associated with such laws. In contrast, the other laws, while related to radiation safety, do not possess the characteristics of a fundamental law and are thus considered individual statutes. Conclusion: The Nuclear Safety Act functions as a fundamental law, the administrative organizations specified in this law would be able to perform functions such as risk determination, management, and judgment under the principles of a rule-of-law state, in relation to the individual laws regulating radiation risks. If it is not feasible for the Nuclear Safety Act to serve as the fundamental law, the normative systems within the individual laws regulating radiation risks must be improved to enable them to perform standardized functions for risk determination, management, and judgment.

Background: In the aftermath of September 11 attacks, the radiobiology community sought novel radiation mitigators capable of preventing death when administered 24 hours or later after exposure to lethal ionizing radiation. The survival and expansion of normal stem cells are crucial for restoring tissue integrity in time to prevent mortality. While U.S. Food and Drug Administration- approved drugs for acute radiation syndrome primarily target the hematopoietic system, restoring the integrity of the intestinal lining is equally important for survival. However, the radiation response of the intestinal stem cell (ISC) population and its niche environment is not as well understood as that of the bone marrow. The aim of this study is to explore early transcriptomic changes in the small intestine after a lethal dose of total body irradiation (TBI) and during subsequent recovery. Materials and Methods: C3H/Sed/Kam mice were irradiated with a TBI dose of 16 Gy, the published 70% lethal dose within 10 days. The compound 1-[(4-nitrophenyl)sulfonyl]-4-phenylpiperazine (NSPP) was administered 24 hours post-irradiation. RNAs from the proximal duodenum were extracted at 28, 72, and 96 hours post-irradiation and subjected to RNA-sequencing. Differentially expressed genes were analyzed using gene-set enrichment analysis. Results and Discussion: Radiation induced significant transcriptomic changes known to precede the death of lymphatic endothelial and epithelial cells. Upregulation of Lgr5+ ISC gene signature was observed during recovery. NSPP treatment further amplified the activation of ISCassociated genes and other regenerative markers. Notably, gene Psrc1 showed strong activation throughout the recovery process, highlighting its potential role in this regenerative response. Conclusion: Our findings highlight potential additional intervention points for mitigating radiation- induced damage in the intestines beyond solely targeting programmed cell death. These insights may contribute to the development of more effective radioprotective approaches, ultimately improving clinical outcomes for individuals undergoing radiotherapy or exposed to highdose radiation.

Background: Accurate quantification of surface dose is critical in radiation therapy, particularly for patients with breast cancer, for whom the risk of cutaneous toxicity is substantial. In this study, we evaluated the clinical feasibility of a novel flexible radiochromic film specifically designed to improve adhesion and usability on curved anatomic surfaces. Materials and Methods: The study prospectively enrolled 20 patients with breast cancer undergoing volumetric modulated arc therapy. Surface dose was measured using flexible radiochromic film placed near the surgical scar and close to the isocenter. Calibration curves were established using a 6 MV photon beam with flattening filter free and without, and the film response was analyzed in both transmission and reflection scanning modes. The measured surface doses were then compared with those calculated by the treatment planning system (TPS). Results and Discussion: The flexible radiochromic film demonstrated excellent sensitivity in the 1.5–2.5 Gy dose range, with superior performance observed in the transmission scanning mode. The film adhered securely to skin without requiring additional fixation and was removed without causing discomfort to the patient. Notably, substantial discrepancies were found between the measured and TPS-calculated surface doses, underscoring the limitations of a TPS in accurately modeling skin dose. Conclusion: Flexible radiochromic film demonstrated dosimetric performance similar to that of conventional films while offering enhanced flexibility and ease of clinical use. Given the significant uncertainty in TPS-based surface-dose estimation, the film provides accurate and practical in vivo surface-dose assessment in breast cancer radiotherapy.

Background: Iridium-192 (192Ir) is one of the radioisotopes most commonly utilized for industrial radiography worldwide. In accordance with the Nuclear Safety Act of the Republic of Korea, the use of projectors containing 192Ir sources requires conducting a shielding evaluation for a given workplace. This evaluation usually uses gamma constants and half-value layers (HVLs). However, significant differences in these values among references can result in over- or underestimation of values. Materials and Methods: The radiological characteristics of the gamma constant and HVL of 192Ir sources employed in industrial radiography were studied with a focus on the effects of source configurations and usage conditions. The source configurations were categorized into point source, volume source (lateral/upward direction), and encapsulated source. The usage conditions, defined by variations in the lead thickness and the distance among the source, lead shield, and tally, enabled derivation of the HVL. Monte Carlo N-Particle version 6.2 (MCNP6.2) was used in these calculations. Results and Discussion: The gamma constant substantially varied depending on the source configuration, exhibiting up to 43%-lower dose rates for the volume source oriented in an upward direction in comparison to the point source. In contrast, usage conditions substantially affected the HVL, which increased from 3.27 mm to 5.51 mm depending on the lead thickness under the broad-beam geometry. Furthermore, the HVLs under narrow-beam conditions were approximately 16.49% lower than those under the broad-beam geometry. Conclusion: A method with new data on the gamma constants and HVLs for shielding evaluation of industrial radiography with 192Ir was presented. The relevant findings resolve inconsistencies in the data presented in the literature and enhance shielding evaluation accuracy. The proposed method not only provides practical standards for shielding evaluations but also ensures regulatory consistency.

The linear no-threshold (LNT) model has long served as a foundational principle in radiation protection. In recent years, advances in radiation health science, along with legal and social debate over the model’s application in administrative and judicial decision-making across nuclear and radiation-related fields—including industry, regulation, and public health—have renewed scrutiny of its scientific basis, regulatory relevance, and societal implications, especially at low doses. This article summarizes the 2025 Winter Workshop hosted by the Korean Association for Radiation Protection, which examined the LNT model through the lenses of science, policy, and societal debate. Key themes included the international rationale and historical basis for the model’s adoption; biological and epidemiological evidence relevant to its evaluation; the regulatory and socioeconomic impacts of radiation protection standards grounded in the LNT model; public perceptions of radiation risk shaped by this framework; and the legal and policy issues arising from its continued use in governance. Rather than reaching a singular conclusion, the workshop highlighted the importance of sustained interdisciplinary dialogue to refine how the LNT model is interpreted and applied across science, regulation, and society—ensuring that resulting approaches remain scientifically robust, socially responsive, and adaptable to evolving evidence.