Journal of Radiological Protection最新文献

Radiological medical imaging services aim to provide a high standard of anatomical imaging to aid diagnosis and treatment of patients' diseases. The services depend on use of the latest techniques to perform the procedures requested reliably with the minimum amount of radiation. Developing and improving such systems requires attention to prevention of any errors in the process and potential refinements in optimising radiological protection. Prevention of incidents requires any unnecessary exposure that does occur to be investigated, events analysed to identify points of potential failure and action taken to address any deficiencies. Optimisation of radiological protection and reduction of imaging dose require understanding and awareness of the techniques and how they might be adapted for individual patients. Both require staff educated and trained in imaging techniques who build on their experience and develop the services with time. Systems for prevention of incidents and optimisation of radiological protection are not just based on assessment, protocol design and analysis when imaging equipment is installed but involve continual review so that improvement becomes part of an established culture within the organisation. Issues requiring particular attention have been highlighted by the International Atomic Energy Agency and the International Commission on Radiological Protection has further expanded the discussion on some of these issues in recent publications. These deal with ethics in radiological protection for patients in treatment and diagnosis and optimisation of radiological protection in imaging. This paper draws these aspects together to emphasise common elements in the requirements and approaches as well as the need for the continual refinement to become part of the radiation safety culture within the organisation.

Fecal radiobioassay is a crucial and sensitive tool for estimating internal exposure and intake of actinides following radioactive or nuclear incidents. This study developed an analytical method to determine²³⁷Np in feces, utilizing TEVA resin for separation and purification, followed by detection with inductively coupled plasma mass spectrometry. By introducing²⁴²Pu as a chemical homologue tracer, which shares similar chemical behaviour with²³⁷Np in the tetravalent state, we effectively monitored the chemical recovery of the target nuclide. We systematically optimised sample pretreatment steps, such as calcination temperature and redox conditions, along with key parameters in the TEVA resin separation process, including sample acidity and elution volume, significantly enhancing the separation and purification efficiency of²³⁷Np. Experimental results indicated average chemical recoveries of 79% for²³⁷Np and 82% for²⁴²Pu. Furthermore, multiple repeated experiments effectively verified the method's accuracy and reliability. The established analytical procedure is practical and yields stable results, providing robust technical support for accurately quantifying²³⁷Np in feces, with significant applications in radiation protection and public health monitoring.

Computed tomography (CT) is essential to modern clinical practice but contributes substantially to population radiation exposure, particularly in oncology, paediatric and screening pathways. In line with the as low as reasonably practicable principle and IR(ME)R requirements, there is growing interest in the use of artificial intelligence (AI) to reduce dose without compromising diagnostic performance. This work synthesised evidence published between January 2020 and May 2025 on AI-based strategies for CT dose optimisation, including deep learning reconstruction, denoising and workflow automation. A systematic search of PubMed, Scopus and IEEE Xplore identified 1,224 records. After removal of 239 duplicates and screening of abstracts and full texts, 86 studies met the inclusion criteria. Eligible studies reported clinical or patient-based outcomes relating to radiation dose, diagnostic accuracy, image quality or feasibility. Phantom-only work, non-CT imaging and conference abstracts without full text were excluded. Due to methodological heterogeneity, findings were synthesised narratively and grouped by anatomical region and AI application. Across indications, AI consistently enabled substantial dose reductions while maintaining diagnostic adequacy. Chest imaging demonstrated 30%-95% reductions, with ultra-low-dose protocols (∼0.1-0.5 mSv) supporting lung cancer screening and nodule detection. Abdominal and hepatic imaging achieved around 40%-70% dose reduction with preserved lesion visibility. 'Double-low' and 'triple-low' vascular protocols reduced both radiation and iodine by 40%-75%. Paediatric applications reported 50%-95% reductions, in some cases approaching doses comparable to radiography. Workflow AI, including auto-positioning and scan-length optimisation, provided additional independent benefits. However, most studies were single-centre and vendor-supported, and sensitivity for very small or subsolid lesions declined at the lowest doses. Altered image texture at high denoising strengths and limited multicentre validation remain concerns. Overall, AI offers clinically meaningful radiation dose reductions of roughly 40%-90% across multiple CT applications while preserving diagnostic confidence. The strongest evidence relates to chest screening, oncology follow-up, vascular imaging and paediatrics. Successful NHS implementation will require governance, quality assurance, training and multicentre evaluation.

Borated polyethylene (PE) is an effective neutron moderator and absorber in medical linear accelerator shielding; however, there is limited data regarding the required material thickness for adequate neutron attenuation. To address the gap in shielding data, our study systematically quantifies first and equilibrium tenth-value layers (TVLs1 and TVLe) for PE containing 0%, 5% and 30% natural boron by weight from thermal to fast neutrons. Comprehensive Monte Carlo simulations (n= 3504) were performed to estimate TVL thicknesses from thermal to 20 MeV neutrons. A current tally was used to count neutrons exiting the shield and determine thicknesses corresponding to 10% and 1% transmission. Sixteen energies and 73 thicknesses of materials were modelled with statistical uncertainties below 3%. TVL thicknesses were independently validated with particle and heavy ion transport code system using identical simulation parameters. We found that TVL values ranged from 1.3 mm for thermal neutrons in borated polyethylene (BPE), to 50 cm for 20 MeV neutrons in pure PE. In all cases, adding boron to PE reduced the TVL, with the greatest effect at thermal energies, and a smallest effect at 12 MeV. Here we provide the first comprehensive characterisation of BPE's ability to attenuate neutrons, supporting shielding design for medical linear accelerators.

Objective This study aimed to investigate the strength of the correlation between organ doses and four CT dose metrics, and to explore a method for rapidly estimating organ doses in patients undergoing chest-abdominal-pelvic (CAP) CT examinations. Methods We retrospectively collected DICOM images of 43 patients who underwent CAP CT examinations. These images were imported into Archer-CT for organ segmentation and dose calculation. Then, regarding the six radiosensitive organs (spinal cord, lung, esophagus, stomach, liver, and bladder) that were included in the study, various radiation dose metrics were calculated based on size-specific dose estimate (SSDE) derived from equivalent water diameters (Dw), i.e. SSDEcenter based on Dw in the center of the scan range, the SSDEmean based on the mean SSDEs of all slices, and the organ-specific SSDEorgan for various organs, as prescribed in AAPM Report 220. Subsequently, correlation analyses were applied to evaluate the relationship between the organ doses and each radiation dose metric and to derive conversion factors for rapid estimating organ doses. Results The ranked linear correlations of the four dose metrics with each organ dose were as follows, in descending order: SSDEorgan, SSDEmean, CTDIvol, and SSDEcenter. The strongest correlation was found between organ dose to liver and SSDELiver (R² = 0.88). The weakest correlation was found between organ dose to the bladder and SSDEBladder (R² = 0.62), and the R² of the rest of the organ doses to SSDEorgan was around 0.8. The conversion coefficients for estimating organ doses based on SSDEorgan for the spinal cord, lung, esophagus, liver, stomach, and bladder were 0.75, 1.24, 0.89, 1.17, 1.18, and 0.83, respectively. Conclusions Higher correlation were observed between organ doses and SSDEorgan for organs involved in this study during CAP CT examinations. Thus, SSDEorgan can be used to simplify and estimate the individualized organ dose for CAP CT examinations.

A World Health Organisation panel previously recommended the use of hematopoietic cytokines to manage H-ARS within 24 h of exposure to ⩾2 Gy radiation dose, a recommendation that has been endorsed by hematologists and oncologists with expertise in radiation management. Nevertheless, no state-of-the-art consensus has been reached regarding categorical selection of cytokines for emergency scenarios involving accidental exposures where implementation of planned and/or extended countermeasures is certain or likely (International Nuclear and Radiological Event Scale levels 5, 6 and 7) or an exposure from a detonated nuclear weapon. A systematic review of the published literature was conducted (422 citations identified, 391 of which were screened) in non-human primates 9 meeting inclusion criteria), and in reviews of human cases treated with cytokines in a search of the MEDLINE database (1970-present), websites/official publications of major national and international organisations and radiation societies, cytokine reviews and full prescribing information. In contrast to filgrastim, pegfilgrastim and romiplostim, sargramostim augments the differentiation and proliferation of multiple lymphohematopoietic lineages. NHP survival benefits without the support of blood products was reported with sargramostim or pegfilgrastim plus romiplostim. Four cytokine reviews met criteria for summarising published reports of 63 human cases that included at least one case meeting inclusion criteria. Cytokine efficacy was documented when administered at up to 96 h after NHP exposure for sargramostim and at 24 h but not 48 h after exposure for filgrastim, pegfilgrstim or pegfilgrastim plus romiplostim. Ease of use favoured pegfilgrastim (administered weekly x2) and romiplostim (administered once), compared to filgrastim and sargramostim (administered daily x5 and x14, respectively). Formal assessment of the published evidence is urgently needed to provide categorical guidance regarding cytokine use for patient management, and to public health officials involved in establishing a national or shared regional radiation stockpile for immediate use in a mass casualty radiological/nuclear (R/N) emergency.

Computed tomography (CT) contributes disproportionately to medical radiation exposure. While most patients undergo only a few examinations, a subset accumulates high cumulative effective doses (CEDs), raising concern for long-term stochastic risks. Recently, the concept of a recurrent exposure reference level (RERL) has been proposed as a benchmark for cumulative dose monitoring in recurrently imaged patients. To evaluate cumulative radiation exposure from recurrent CT imaging in a tertiary care hospital, determine the proportion of patients exceeding high-dose thresholds, and establish a local RERL. All adult CT examinations performed at Vilnius University Hospital Santaros Klinikos between 2022 and 2024 were retrospectively analysed. Recurrent patients were defined as those with at least one CT in 2023 and an additional CT in 2022, 2023, or 2024. Outcome measures included the annual and three-year incidence and prevalence of CED ⩾ 100 mSv, dose distributions, and RERL determination as the 75th percentile of annual CED among recurrent patients. Over three years, 78 258 patients underwent 99 865 CT examinations. The annual number of patients and exams increased steadily, but the yearly incidence of high-dose patients (CED ⩾ 100 mSv) remained stable at ∼2%. Across the full cohort, 1633 patients (3.6%) exceeded 100 mSv, and 29 patients (0.04%) surpassed 500 mSv. Among 9199 recurrent patients (35.6% of the total), 18.2% exceeded 100 mSv within three years. Most patients (68%) crossed this threshold with fewer than five CTs. The local RERL, defined as the 75th percentile of annual CED in recurrent patients, was 36 mSv. A subset of patients in a tertiary care setting accumulated high radiation doses from recurrent CT, often with relatively few examinations. The derived RERL aligns closely with values reported in other European studies, supporting its use as a practical benchmark for monitoring cumulative dose. Systematic dose tracking, integration of RERLs, and strict adherence to justification and optimisation are essential to mitigate risks while preserving the diagnostic value of CT.

A 1 d workshop on citizen science in radioactivity measurements was organised by the French nuclear safety and radiation protection authority (ASNR) in June 2025 in Brussels, gathering nuclear safety authority representatives, research institutes, citizen radiation measurement networks and civil society representatives. The aim was to provide an overview of currently existing citizen radioactivity measurements projects in Europe, their structures and their objectives. An exhibition of selected technical materials was arranged. Key objectives of the workshop included ensuring the sustainability of citizen initiatives and integrating citizen data into decision-making processes, with a particular focus on widening participation in Eastern Europe. Participants also discussed existing gaps and difficulties and explored potential future projects.

Objective. We report the visualisation of low-level gamma radiation sources in an accelerator-based boron neutron capture therapy (AB-BNCT) facility employing a Li target. In this facility, irradiation of the Li target with accelerated protons produces neutrons and generates a large amount of radioactive7Be with a long half-life of 53 d, while various other radioactive materials are suspected to be produced through neutron activation.Approach. To visualise gamma rays emitted from these radioactive materials across a wide energy range with high sensitivity, we prepared a high-sensitivity omnidirectional rotating Compton camera comprising six 3.5 cm × 3.5 cm × 3.5 cm CsI(Tl) scintillator cubes mounted on a motorised rotation stage. Measurements were carried out in the irradiation room 24 h after neutron irradiation.Main result. No leakage of7Be from the Li target into the irradiation room was detected. However, some radioactive materials with long half-lives were observed in the irradiation port and on the bed. Additionally, gamma rays from7Be remaining in a spent Li target, previously removed from the irradiation port and stored, were visualised.Significance. The Compton camera technique proposed and used in this study is shown to be effective for monitoring radioactive materials within AB-BNCT facility.

The Scientists Who Alerted Us to the Dangers of Radiation was published in 2024 with the aim to demonstrate that radiation-induced stochastic effects are far more severe than admitted by the nuclear establishment and to describe biographies of 39 scientists who found supporting evidence but whose reports were often harshly treated by officialdom when they tried to publicise or even report it. The book also contains 14 scientific appendices where the evidence is shortly described, and conclusions and recommended actions for improving the system of radiological protection are given. In my opinion, the book is a classic example of conspiracy theory and confirmation bias, and as such, a useful resource for teaching about these phenomena.