This paper provides a critical review of a paper published in an earlier edition of the journal.
This paper provides a critical review of a paper published in an earlier edition of the journal.
Accurate estimation of fetal dose during computed tomography (CT) examinations is essential to ensure fetal safety. This study presents a comparative analysis of six Monte Carlo software tools (VirtualDose CT, FetalDose.org, CODE, Waza-ari, ImPACT, and CT-Expo) for fetal dose estimation across various CT examinations, representing the largest number of tools assessed to date. By integrating reliability analysis with performance evaluation, the study improves the selection of fetal dose software tools in radiology practice. The tools were used to estimate fetal doses for 26 pregnant participants who underwent 27 CT examinations. Single and average measures intraclass correlation coefficient (ICC) values were calculated to assess both collective and pairwise reliability. Agreement between the most reliable tool pair was evaluated using a Bland-Altman plot. Performance comparative analysis for the software tools in estimating fetal dose from CT was conducted via a weighted scoring method, considering accuracy, safety, and usability. The average measures ICC for all tools was 0.96 (95% CI: 0.91 - 0.98), indicating excellent overall reliability, while the single measures ICC value of 0.80 (95% CI: 0.63 - 0.90) reflected moderate to excellent reliability of an individual software tool with the others. VirtualDose CT and FetalDose.org showed the highest single measures ICC of 0.98 (95% CI: 0.96 - 0.99), demonstrating a high reliability between both tools. The Bland-Altman analysis for these two tools showed a mean difference of 0.79 and limits of confidence from -2.45 to 4.03, indicating a good agreement and further confirming their reliability. In terms of performance comparative analysis, VirtualDose CT outperformed the other tools with a total score of 485.25 based on the evaluation criteria. In conclusion, VirtualDose CT is recommended as the preferred software for fetal dose estimation in CT examinations due to its superior performance and reliability.
Crew members on missions beyond low-earth orbit receive considerable radiation doses, but the effects and relative biological effectiveness of many relevant types of irradiation, including neutrons with energies of hundreds of MeV, largely remain under-investigated. Such small animal irradiations can only be compared to respective photon irradiations if comparable doses can simultaneously be delivered to a variety of organs during both irradiations, despite the different underlying dose deposition patterns. To evaluate the dosimetric comparability of upcoming small animal neutron and photon irradiations, experimental depth-dose measurements were performed at the TRIUMF neutron facility and the British Columbia Cancer Research Centre, using a neutron beam with energies of up to 450 MeV and a Cs-137 irradiator. The MOBY digital mouse phantom was used to perform Monte Carlo simulations of neutron and photon animal irradiations. Evaluated metrics included the ratio between the dose delivered to a variety of different organs (including lungs, brain, and heart) during neutron and photon irradiation. A sensitivity analysis including a variety of animal parameters (tissue elemental compositions and mass densities, animal size, and animal orientation) was performed, and the statistical significance (p< 0.05) of the dosimetric impact of uncertainties in simulation parameters was analyzed. During nominal simulations, differences in organ doses during neutron and photon irradiation were <9% in all organs except the lungs (13%), in agreement with the dosimetric measurements performed, which exhibited differences of up to ≈20% depending on depth. During sensitivity analysis, no investigated source of uncertainty had a statistically significant dosimetric impact. Organ doses during simulated neutron and photon irradiations were found to be comparable for various organs. Investigated sources of uncertainties had no statistically significant impact. These findings are therefore expected to be robust to realistic variations in animal parameters during upcoming small animal irradiations.
Personal radiation protective equipment (PRPE) play a critical role in minimising occupational exposure to ionising radiation in medical imaging, nuclear medicine, interventional procedures and related fields. Over time, repeated use, mechanical stress, and improper handling can degrade their protective performance, making regular inspection essential to ensure continued radiation safety. This study aimed to compare the performance of multiple imaging modalities in evaluating the integrity and lead equivalence of PRPE, to identify the most accurate and practical methods for quality assurance programmes. Over a four-year period, 1063 PRPE items from 20 manufacturers were evaluated. Each item underwent visual and tactile inspection, followed by imaging using radiography, fluoroscopy, computed tomography (CT), and a dedicated PRPE testing system (FLOWD 8020). Lead equivalence was determined by comparison with certified reference lead foils using both x-ray quality assurance dosimeter and image-based methods. Integrity was categorised on a four-level scale according to defect size and location, and attenuation performance was assessed relative to manufacturers' nominal specifications. Of all PRPE items tested, 88.8% were defect-free, while 11.2% showed cracks or tears cracks or tears of varying extent. Lead equivalence results revealed that 74.3% met specifications within ±5%, 13.8% deviated by 5%-10%, and 11.9% by more than 10%. All imaging modalities demonstrated comparable accuracy, though the dedicated screening system offered clear advantages in workflow efficiency, full-apron coverage, automated reporting, and low stray dose (<0.3μSv h-1at 1 m). Routine PRPE inspection is essential for maintaining occupational radiation safety. Standardised testing protocols and inspection intervals are recommended to ensure consistent and traceable quality assurance practices across institutions.
Rapid and accurate evaluation of gamma radiation dose in dynamic virtual environments is crucial for radiation protection and safety assessment. The point kernel method has been widely used for rapid dose calculation due to its high efficiency. However, the 'point kernel calculations (PKCs) count' is defined as the product of the point kernels number and the counting grids number. Consequently, when either the number of point kernels generated from the discretised radiation source or the number of counting grids in the space becomes large, the time consumption increases significantly. This issue is further exacerbated when the geometric model is no longer a regular geometry describable by mathematical formulas but rather an arbitrary 3D model in a virtual environment, where the cost of ray tracing grows substantially. To address this challenge, an efficient computational approach is proposed and a high-performance point kernel code, PLSPK, is developed in this work. The main features of PLSPK include using triangular mesh models as geometric representations to handle arbitrary shapes, and optimising the ray-tracing process through the application of the maximised-parallelism bounding volume hierarchy technology, enabling rapid selection of target triangles for ray tracing in complex scenes. Furthermore, by leveraging graphics processing unit parallel computation, the code significantly accelerates large-scale PKC in gamma radiation fields, allowing PLSPK to meet the demand for continuous rapid updates of radiation field in dynamic environments. Compared with serial implementations, the acceleration achieved by PLSPK becomes more pronounced as the PKC count (PKC count) increases, when the PKC count reaches 1E + 06, the speedup is approximately 2000×, with small impact from scene complexity. Accuracy validation against existing point kernel codes and the Monte Carlo particle transport program MCNP demonstrates that PLSPK provides reliable dose estimations. These features make PLSPK a reliable tool for high-efficiency gamma radiation field calculation in complex dynamic virtual environments.
Neutron dose assessment in radiation accidents relies on measuring induced2⁴Na activity via the23Na(n,γ)2⁴Na reaction. However, the effect of body size on neutron moderation, gamma self-absorption, and organ distribution-remains poorly quantified, with conflicting literature reports. To systematically evaluate the body size effect on neutron absorbed dose and2⁴Na yield, four human voxel phantoms of different body sizes (5-, 10-, 15-, and 38 year-old individuals) were irradiated in MCNP simulations with2⁵2Cf and 28 monoenergetic neutron sources (10-9-20 MeV) under six geometries. The neutron absorbed dose, induced2⁴Na activity per unit mass, and the conversion coefficients between24Na activity per unit mass and neutron absorbed dose were calculated. The results show that body size significantly affects the neutron dose. When the human body is irradiated with2⁵2Cf neutrons under different irradiation geometries, the conversion coefficients between2⁴Na activity per unit mass and neutron absorbed dose are at least 48.3% larger in adults than in 5 year-old children. When the human body is irradiated with monoenergetic neutrons under isotropic irradiation geometry, these conversion coefficients decrease with increasing body size for neutron energies <0.1 MeV, and increase with increasing body size for neutron energies >0.1 MeV. For 10-9MeV neutron irradiation, the coefficient for adults is 26.5% smaller than that of 5 year-old children. Conversely, for 20 MeV neutron irradiation, the coefficient for adults is 114.2% larger than that for 5 year-old children.
The differences in risk perception between women and men regarding the health effects of radiation following nuclear disasters are well documented. In particular, after the 2011 Fukushima accident, mothers with young children exhibited higher levels of risk perception and a greater tendency toward prolonged depression. However, the broader social context underlying women's heightened depressive symptoms has received little attention. To address this gap, this study analysed the publicly available 2014 records of the International Commission on Radiological Protection Fukushima Dialogue-a stakeholder meeting held in Fukushima Prefecture-focusing on discussions about child-rearing and the dynamics of participant interaction. The analysis revealed that women with young children in Fukushima were subject to strong normative expectations. While these expectations were often experienced as a burden, the women also internalised them and took on the responsibility of motherhood as their own. Such expectations simultaneously constrained women's capacity for independent social action and demanded that they protect their children from radiation exposure. This contradiction-being expected to meet both demands at once-constitutes a double bind. The findings indicate that, in the aftermath of the accident, women with young children in Fukushima were indeed caught in such a situation, shaped by the prevailing social context.
Protecting medical personnel from the harmful effects of scattered ionising radiation during x-ray-guided procedures is a critical concern. Due to the complex and invisible nature of x-rays, monitoring radiation exposure has been challenging. Existing real-time dosimeters have shown low accuracy and practical limitations. To address these challenges, this study introduces an innovative approach that combines Monte Carlo (MC) simulations and deep learning (DL) for real-time estimation of three-dimensional (3D) scattered radiation in the operating room. The neural network was trained to map patient morphology and imaging parameters to radiation maps, allowing it to adapt to various clinical scenarios. The results demonstrate that the system showcases exceptional speed by efficiently computing 3D radiation maps in 11 ms using modern GPU (NVIDIA RTX 2080). Validation experiments confirmed the reliability of the predicted scatter maps, with a mean absolute percentage error of 10.97% relative to MC simulations. When used to compute organ doses via voxelised-source simulations, the global average organ dose error was 8.2 ± 4.1%. Therefore, the combination of MC simulations and DL provides a promising solution for enhancing the safety of medical personnel during x-ray-guided procedures.
The Fire Rescue Service of the Czech Republic is a key component of the integrated rescue system, ensuring the protection of the population, the environment, and property from the effects of fires, chemical accidents, and radiation incidents. Given the changing security situation in Europe and growing technological demands, it is necessary to analyse the preparedness and activities of members of the Fire Rescue Service of the Czech Republic in the area of chemical services and radiation protection. The aim of the study was to evaluate the current state of professional training, equipment, and ethical aspects of interventions, and to propose measures to increase the effectiveness of the system. Methodologically, the work is based on qualitative research of professional literature and evaluation using SWOT analysis, which identifies the strengths and weaknesses of the system, opportunities, and threats. The results show that the Fire Rescue Service of the Czech Republic has a robust training system and technical facilities, but faces challenges in the areas of integrating new technologies, the mental resilience of responders, and ethical decision-making. The study recommends expanding training to include augmented reality simulations, supporting research into environmentally friendly shielding materials, and introducing ethical protocols for interventions in contaminated environments.
Disasters have a wide range of effects on society. Nuclear disasters require a multifaceted response that considers the direct health effects of radiation exposure and indirect health consequences associated with evacuation. In recent years, the development and evaluation of practical nuclear disaster preparedness measures have become critical challenges for regions hosting nuclear power plants due to the growing risk of increasingly complex natural hazards. This study aimed to clarify the operational challenges of radiation-shielded shelter facilities used for sheltering during disasters by investigating the damage sustained by such facilities in Shika Town, Ishikawa Prefecture, where a seismic intensity of 7 was recorded during the 2024 Noto Peninsula Earthquake. The study was conducted through interviews and analysis of official damage reports by the Cabinet Office, targeting 12 radiation-protective facilities equipped with positive-pressure systems located within the Precautionary Action Zone (PAZ) and the Urgent Protective Action Planning Zone of the Shika Nuclear Power Plant. The results identified two major operational issues: (1) a lack of shared understanding regarding the target pressure differentials for positive-pressure systems and (2) a decline in building airtightness due to structural damage caused by the earthquake. In addition, insufficient sharing of knowledge and operational criteria between administrative authorities and on-site personnel has emerged as a challenge for the practical use of these facilities. These findings underscore the need for standardised criteria for seismic resistance and airtightness that assume the occurrence of compound disasters, as well as the importance of strengthening information-sharing systems during normal times. Furthermore, the study highlights that even within the PAZ, older individuals and persons requiring special care may face difficulties in executing immediate evacuation, potentially making sheltering-in-place the only feasible option. Therefore, it is necessary to reconsider the institutional position of sheltering as a realistic form of evacuation.
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