Neutron dose evaluation inside high-energy accelerator irradiation vault using LR-115.

Recently, a new radiation therapy using a high-energy accelerator irradiation vault has attracted significant attention. This therapy is very effective in destroying cancer cells because it uses much higher energy than conventional radiation therapy. Nevertheless, it also has disadvantages due to its high energy and dose, resulting in the generation of secondary radiation such as X-rays and neutrons. In particular, neutrons have a higher radiation weighting factor than photons; therefore, they are more harmful to normal tissues. However, the popular neutron dosimeter CR-39 cannot evaluate high-dose neutrons. This paper proposes a novel method for measuring high-dose neutrons generated during cancer treatment. LR-115, which has low detection efficiency but is expected to be useful for evaluating high-dose neutrons, was used to evaluate the effective dose of neutrons in a high-energy accelerator irradiation room. The results were verified using MCNP 6.2, a Monte Carlo-based particle transport code. This study provides the lower limit for evaluating neutron effective dose using LR-115. The experimental results showed that the neutron effective dose increased linearly with beam current. These findings provide basic data for evaluating neutron effective dose for radiation protection.

An investigation into the knowledge, attitudes, and practice of radiation protection in interventional radiology and cardiac catheter-laboratories.

BACKGROUND: According to current literature, there is a lack of information regarding the radiation protection (RP) practices of interventional radiology (IR) and cardiology catheter laboratory (CCL) staff. This study aims to determine the RP practices of staff within IR and CCLs internationally and to suggest areas for improvement. METHODS: A cross-sectional study in the form of an online questionnaire was developed. Participation was advertised via online platforms and through email. Participants were included if they were healthcare professionals currently working in IR and CCLs internationally. Questionnaire design included Section 1 demographic data, Section 2 assessed RP training and protocols, Section 3 surveyed the use of different types of RP lead shields, both personal and co-worker use and Section 4 assessed other methods of minimising radiation dose within practice. Questions were a mix of open and closed ended, descriptive statistics were used for closed questions and thematic analysis was employed for open ended responses. RESULTS: A total of 178 responses to the questionnaire were recorded with 130 (73 %) suitable for analysis. Most respondents were female (n = 94, 72 %) and were radiographers (n = 97, 75 %). Only 68 (53 %) had received training, the majority receiving this in-house (n = 54, 79 %). 118 (98 %) of respondents had departmental protocols in place for RP. Radiology managers (n = 106, 82 %) were most likely to contribute to such protocols. Multiple methods of dose minimisation exist, these include low-dose fluoroscopy, staff rotation, radiation dose audits and minimal time in the controlled areas. Respondents reported that lead apron shields were wore personally by 99 % of respondents and by co-workers in 95 % of cases. CONCLUSION: The practices of RP by IR and CCL staff in this survey was variable and can be improved. The unavailability of basic radiation protection tools and RP specific training courses/modules were some of the reasons for sub-optimal self-protection against ionising radiation reported by respondents.

A multicentre survey of knowledge and implementation of radiation protection techniques in cardiac cath-lab medical personnel.

BACKGROUND: Awareness of radiation hazards and methods to reduce radiation dose is a sine qua non for all staff working in the cath-lab for their own safety and their patient's safety. RESULTS: There were large variations in the implementation of radiation protection techniques with overall inadequate radiation risk knowledge. Some members of the cath-lab team are at higher risk of radiation-induced side effects, including the fellows, nurses, technicians, and anaesthesiologists because they spent longer time in the cath-lab and/or their position in relation to the source of radiation. About 10% of the participants have reported different health problems potentially induced by radiation exposure. CONCLUSIONS: There is lack of radiation risks knowledge with inadequate radiation protection practice among cath-lab team. Some members such as fellows, nurse, technicians, and cardiac anaesthesiologist are at higher risks. They represent the forgotten members of the Cath-Lab team.

Monte Carlo modelling of cyclotron and radioisotope center (CYRIC) at Tohoku University: a radiation protection study.

Protection against ionizing radiations is important in laboratories with radioactive materials and high energy cyclotron beams. The Cyclotron and Radioisotope Center (CYRIC) located in Tohoku University in Miyagi prefecture, Japan and is a well-known nuclear science laboratory with cyclotron beams and substantial number of high activity radioactive materials. Considering this, it is important to perform complete radiation transport computations to ensure the safety of non-occupational and occupational workers. In the present work, we have developed a complete 3-dimensional model of the main cyclotron building and radiation labs using Monte Carlo method. We have found that the dispersed photons and neutrons inside and in the surrounding of the CYRIC building pose no significant risk to occupational and non-occupational workers. The present work and the developed models would be useful in the field of radiation protection.

Object and person tracking systems to enable extremity dosimetry in nuclear medicine using computational methods.

Nuclear medicine (NM) professionals are potentially exposed to high doses of ionising radiation, particularly in the skin of the hands. Ring dosimeters are used by the workers to ensure extremity doses are kept below the legal limits. However, ring dosimeters are often susceptible to large uncertainties, so it is difficult to ensure a correct measurement using the traditional occupational monitoring methods. An alternative solution is to calculate the absorbed dose by using Monte Carlo simulations. This method could reduce the uncertainty in dose calculation if the exact positions of the worker and the radiation source are represented in these simulations. In this study we present a set of computer vision and artificial intelligence algorithms that allow us to track the exact position of unshielded syringes and the hands of NM workers. We showcase a possible hardware configuration to acquire the necessary input data for the algorithms. And finally, we assess the tracking confidence of our software. The tracking accuracy achieved for the syringe detection was 57% and for the hand detection 98%.

[Artificial intelligence in diagnostic radiology for dose management : Advances and perspectives using the example of computed tomography]. / Künstliche Intelligenz im Dosismanagement der diagnostischen Radiologie : Entwicklungen und Perspektiven am Beispiel der Computertomographie.

CLINICAL-METHODOLOGICAL PROBLEM: Imaging procedures employing ionizing radiation require compliance with European directives and national regulations in order to protect patients. Each exposure must be indicated, individually adapted, and documented. Unacceptable dose exceedances must be detected and reported. These tasks are time-consuming and require meticulous diligence. STANDARD RADIOLOGICAL METHODS: Computed tomography (CT) is the most important contributor to medical radiation exposure. Optimizing the patient's dose is therefore mandatory. Use of modern technology and reconstruction algorithms already reduces exposure. Checking the indication, planning, and performing the examination are further important process steps with regard to radiation protection. Patient exposure is usually monitored by dose management systems (DMS). In special cases, a risk assessment is required by calculating the organ doses. METHODOLOGICAL INNOVATIONS: Artificial intelligence (AI)-assisted techniques are increasingly used in various steps of the process: they support examination planning, improve patient positioning, and enable automated scan length adjustments. They also provide real-time estimates of individual organ doses. EVALUATION: The integration of AI into medical imaging is proving successful in terms of dose optimization in various areas of the radiological workflow, from reconstruction to examination planning and performing exams. However, the use of AI in conjunction with DMS has not yet been considered on a large scale. PRACTICAL RECOMMENDATION: AI processes offer promising tools to support dose management. However, their implementation in the clinical setting requires further research, extensive validation, and continuous monitoring.

In-depth exploration of the radiation exposure to staff performing endoscopic retrograde cholangiopancreatography procedures (ERCP) through RANDO phantom and TLDs.

This study provides a comprehensive evaluation of the occupational radiation exposure faced by healthcare professionals during Endoscopic Retrograde Cholangiopancreatography (ERCP) procedures. Utilizing an anthropomorphic RANDO phantom equipped with Thermoluminescent Dosimeters (TLDs), we replicated ERCP scenarios to measure radiation doses received by medical staff. The study meticulously assessed radiation exposure in various corresponding body regions typically occupied by medical staff during ERCP, with a focus on eyes, thyroid, hands, and reproductive corresponding organ regions. The findings revealed significant variations in radiation doses across different body parts, highlighting areas of higher exposure and underscoring the need for improved protective measures and procedural adjustments. The effective radiation doses were calculated using standard protocols, considering the varying levels of protection offered by lead aprons and thyroid shields. The results demonstrate the substantial radiation exposure experienced by healthcare staff, particularly in regions not adequately shielded. This study emphasizes the necessity for enhanced radiation safety protocols in clinical settings, advocating for advanced protective equipment, training in radiation safety, and the exploration of alternative imaging modalities. The findings have crucial implications for both patient and staff safety, ensuring the continued efficacy and safety of ERCP and similar interventional procedures. This research contributes significantly to the field of occupational health and safety in interventional radiology, providing vital data for the development of safer medical practices.

Staff radiation doses during Sentinel Lymph Node procedure of breast cancer from injection to surgeon.

The Sentinel Lymph Node (SLN) or Sentinel Lymph Node Biopsy (SLNB) technique involves various professionals from different departments in clinical settings to manage breast cancer patients properly. Tracing the nodular involvement of breast cancer patients requires radiation source Tc99m labeled with colloidal albumin to be injected at the tumor site. The patient becomes a radiation source for a sufficient time, which concerns the Nuclear Medicine (NM) and surgical staff. The study aims to provide the radiation doses of staff in the NM department during the SLN scintigraphy procedure and obtain an empirical model for calculating the radiation doses to staff in the surgical department from that particular patient. Radiation doses in SLN technique for breast cancer patients are minimal, and a sufficient number of SLN biopsy procedures can be performed by hospital staff within the category of non-radiation workers.

Effect of backscatter radiation on the occupational eye-lens dose.

We quantified the level of backscatter radiation generated from physicians' heads using a phantom. We also evaluated the shielding rate of the protective eyewear and optimal placement of the eye-dedicated dosimeter (skin surface or behind the Pb-eyewear). We performed diagnostic X-rays of two head phantoms: Styrofoam (negligible backscatter radiation) and anthropomorphic (included backscatter radiation). Radiophotoluminescence glass dosimeters were used to measure the eye-lens dose, with or without 0.07-mm Pb-equivalent protective eyewear. We used tube voltages of 50, 65 and 80 kV because the scattered radiation has a lower mean energy than the primary X-ray beam. The backscatter radiation accounted for 17.3-22.3% of the eye-lens dose, with the percentage increasing with increasing tube voltage. Furthermore, the shielding rate of the protective eyewear was overestimated, and the eye-lens dose was underestimated when the eye-dedicated dosimeter was placed behind the protective eyewear. We quantified the backscatter radiation generated from physicians' heads. To account for the effect of backscatter radiation, an anthropomorphic, rather than Styrofoam, phantom should be used. Close contact of the dosimeter with the skin surface is essential for accurate evaluation of backscatter radiation from physician's own heads. To assess the eye-lens dose accurately, the dosimeter should be placed near the eye. If the dosimeter is placed behind the lens of the protective eyewear, we recommend using a backscatter radiation calibration factor of 1.2-1.3.

Estimating brain and eye lens dose for the cardiologist in interventional cardiology-are the dose levels of concern?

OBJECTIVES: To establish conversion coefficients (CCs), between mean absorbed dose to the brain and eye lens of the cardiologist and the air kerma-area product, PKA, for a set of projections in cardiac interventional procedures. Furthermore, by taking clinical data into account, a method to estimate the doses per procedure, or annual dose, is presented. METHODS: Thermoluminescence dosimeters were used together with anthropomorphic phantoms, simulating a cardiologist performing an interventional cardiac procedure, to estimate the CCs for the brain and eye lens dose for nine standard projections, and change in patient size and x-ray spectrum. Additionally, a single CC has been estimated, accounting for each projections fraction of use in the clinic and associated PKA using clinical data from the dose monitoring system in our hospital. RESULTS: The maximum CCs for the eye lens and segment of the brain, is 5.47 µGy/Gycm2 (left eye lens) and 1.71 µGy/Gycm2 (left brain segment). The corresponding weighted CCs: are 3.39 µGy/Gycm2 and 0.89 µGy/Gycm2, respectively. CONCLUSIONS: Conversion coefficients have been established under actual scatter conditions, showing higher doses on the left side of the operator. Using modern interventional x-ray equipment, interventional cardiac procedures will not cause high radiation dose levels to the operator when a ceiling mounted shield is used, otherwise there is a risk that the threshold dose values for cataract will be reached. ADVANCE IN KNOWLEDGE: In addition to the CCs for the different projections, methods for deriving a single CC per cardiac interventional procedure and dose per year were introduced.

Radiation Adverse Outcome pathways (AOPs): examining priority questions from an international horizon-style exercise.

PURPOSE: The Organisation for Economic Co-operation and Development (OECD) Adverse Outcome Pathway (AOP) Development Programme is being explored in the radiation field, as an overarching framework to identify and prioritize research needs that best support strengthening of radiation risk assessment and risk management strategies. To advance the use of AOPs, an international horizon-style exercise (HSE) was initiated through the Radiation/Chemical AOP Joint Topical Group (JTG) formed by the OECD Nuclear Energy Agency (NEA) High-Level Group on Low Dose Research (HLG-LDR) under the auspices of the Committee on Radiological Protection and Public Health (CRPPH). The intent of the HSE was to identify key research questions for consideration in AOP development that would help to reduce uncertainties in estimating the health risks following exposures to low dose and low dose-rate ionizing radiation. The HSE was conducted in several phases involving the solicitation of relevant questions, a collaborative review of open-ended candidate questions and an elimination exercise that led to the selection of 25 highest priority questions for the stated purpose. These questions were further ranked by over 100 respondents through an international survey. This final set of questions was judged to provide insights into how the OECD's AOP approach can be put into practice to meet the needs of hazard and risk assessors, regulators, and researchers. This paper examines the 25 priority questions in the context of hazard/risk assessment framework for ionizing radiation. CONCLUSION: By addressing the 25 priority questions, it is anticipated that constructed AOPs will have a high level of specificity, making them valuable tools for simplifying and prioritizing complex biological processes for use in developing revised radiation hazard and risk assessment strategies.

Biomaterials-mediated radiation-induced diseases treatment and radiation protection.

In recent years, the intersection of the academic and medical domains has increasingly spotlighted the utilization of biomaterials in radioactive disease treatment and radiation protection. Biomaterials, distinguished from conventional molecular pharmaceuticals, offer a suite of advantages in addressing radiological conditions. These include their superior biological activity, chemical stability, exceptional histocompatibility, and targeted delivery capabilities. This review comprehensively delineates the therapeutic mechanisms employed by various biomaterials in treating radiological afflictions impacting the skin, lungs, gastrointestinal tract, and hematopoietic systems. Significantly, these nanomaterials function not only as efficient drug delivery vehicles but also as protective agents against radiation, mitigating its detrimental effects on the human body. Notably, the strategic amalgamation of specific biomaterials with particular pharmacological agents can lead to a synergistic therapeutic outcome, opening new avenues in the treatment of radiation- induced diseases. However, despite their broad potential applications, the biosafety and clinical efficacy of these biomaterials still require in-depth research and investigation. Ultimately, this review aims to not only bridge the current knowledge gaps in the application of biomaterials for radiation-induced diseases but also to inspire future innovations and research directions in this rapidly evolving field.

Occupational radiation exposure among medical personnel in university and general hospitals in Japan.

OBJECTIVE: This study aimed to compare the occupational radiation exposure of medical workers between general hospitals and university hospitals. METHODS: Radiation exposure data from three hospitals in Hiroshima city, including one university hospital and two general hospitals, were collected using personal dosimeters. Monthly radiation doses were analyzed, and the annual sum of radiation exposure dose was calculated for 538 subjects in general hospitals and 1224 subjects in the university hospital. To assess the impact of locality, additional data from Nagasaki University Hospital and Fukushima Medical University Hospital were included for comparative analysis. Professional affiliations, such as doctors, nurses, and radiological technologists, were considered in the evaluation. RESULTS: The study revealed slight but significant differences in radiation doses between general and university hospitals. In general hospitals, except for radiological technologists, a slightly higher radiation dose was observed compared to university hospitals. Despite the annual increase in the use of medical radiation, the majority of hospital workers in both settings adhered to safety guidelines, with occupational radiation exposure remaining below the limit of detection (LOD). Workers who involved in fluoroscopic procedure, whether at university or general hospitals, had higher radiation doses than those who did not. CONCLUSION: The study's primary conclusion is that workers in general hospitals experience a slight but significantly higher radiation dose and a lower percentage below the LOD compared to university hospitals. The observed difference is attributed to the greater workload at general hospitals than at university hospitals, and also may be due to the different nature of university hospital and general hospital. University hospitals, characterized by greater academic orientation, tend to benefit from comprehensive support systems, specialized expertise, and advanced technology, leading to more structured and regulated radiation control. These findings provide a basis for targeted interventions, improved safety protocols.

Fabrication, Structural Characterization, and Photon Attenuation Efficiency Investigation of Polymer-Based Composites.

Experiments have assessed various polymer composites for radiation shielding in diverse applications. These composites are lighter and non-toxic when compared to lead (Pb), making them particularly effective in diagnostic imaging for shielding against low-energy photons. This study demonstrates the fabrication of four composites by combining a base material, specifically a high-density polyethylene (HDPE) polymer, with 10% and 20% silicon (Si) and silicon carbide (SiC), respectively. Additionally, 5% molybdenum (Mo) was incorporated into the composites as a heavy metal element. The composites obtained were fabricated into 20 disks with a uniform thickness of 2 mm each. Discs were exposed to radiation from a low-energy X-ray source (32.5-64.5 keV). The chemical and physical properties of composites were assessed. The shielding ability of samples was evaluated by determining the linear and mass attenuation coefficients (µ and µm), radiation protection efficiency (RPE), half-value layer (HVL), and mean free path (MFP). According to our findings, supplementing HDPE with additives improved the attenuation of beams. The µm values showed that composite X-ray shielding characteristics were enhanced with filler concentration for both Si and SiC. Polymer composites with micro-molecule fillers shelter X-rays better than polymers, especially at low energy. The HVL and MFB values of the filler are lower than those of the pure HDPE sample, indicating that less thickness is needed to shield at the appropriate energy. HC-20 blocked 92% of the incident beam at 32.5 keV. This study found that increasing the composite sample thickness or polymer filler percentage could shield against low-energy radiation.

Case study with dosimetric analysis: Total body irradiation to a patient with a left ventricular assist device.

Key Clinical Message: A patient presented with cardiogenic shock, requiring the implantation of a left ventricular assist device (LVAD), and acute myeloblastic leukemia. This necessitated total body irradiation (TBI) while balancing dose reduction to the LVAD components to avoid potential radiation damage. Here we outline our treatment approach and dose estimates to the LVAD. Abstract: This case report discusses the delivery of TBI to a patient with an LVAD. This treatment required radiation-dose determinations and consequential reductions for the heart, LVAD, and an external controller connected to the LVAD. The patient was treated using a traditional 16MV anterior posterior (AP)/posterior anterior (PA) technique at a source-to-surface-distance of 515 cm for 400 cGy in two fractions. A 3 cm thick Cerrobend block was placed on the beam spoiler to reduce dose to the heart and LVAD to 150 cGy. The external controller was placed in a 1 cm thick acrylic box to reduce neutron dose and positioned as far from the treatment fields as achievable. In vivo measurements were made using optically stimulated luminescence dosimeters (OSLDs) placed inside the box at distances of 2 cm, 8.5 cm, and 14 cm from the field edge, and on the patient along the central axis and centered behind the LVAD block. Further ion chamber measurements were made using a solid water phantom to more accurately estimate the dose delivered to the LVAD. Neutron dose measurements were also conducted. The total estimated dose to the controller ranged from 135.3 cGy to 91.5 cGy. The LVAD block reduced the surface dose to the patient to 271.6 cGy (68.1%). The block transmission factors of the 3 cm Cerrobend block measured in the phantom were 45% at 1 cm depth and decreased asymptotically to around 30% at 3 cm depth. Applying these transmission factors to the in vivo measurements yielded a dose of 120 cGy to the implanted device. The neutron dose the LVAD region is estimated around 0.46 cGy. Physical limitations of the controller made it impossible to completely avoid dose. Shielding is recommended. The block had limited dose reduction to the surface, due to secondary particles, but appropriately reduced the dose at 3 cm and beyond. More research on LVADs dose limits would be beneficial.

Expansion of Typical Values for Paediatric Patients in Ireland and Comparison with Published DRLs - Experiences of a Single Institution.

INTRODUCTION: To reduce the risks involved with ionising radiation exposure, typical values (TVs) and diagnostic reference levels (DRLs) have been established to help keep radiation doses 'as low as reasonably practicable. TVs/DRLs provide standardised radiation dose metrics that can be used for comparative purposes. However, for paediatrics, such values should consider the size of the child instead of their age. This study aimed to establish and compare paediatric TVs for chest, abdomen and pelvis radiography. METHODS: Study methods followed processes for establishing paediatric DRLs as outlined by the Health Information and Quality Authority (HIQA). Kerma-area product (KAP) values, excluding rejected images, were retrospectively acquired from the study institution's Picture Archiving and Communications System (PACS). Paediatric patients were categorised into the following weight-based groupings (5 to <15 kg, 15 to <30 kg, 30 to <50 kg, 50 to 80 kg) and stratified based on the examination that was performed (chest, abdomen, and pelvis), and where it was performed (the different X-ray rooms). Anonymised data were inputted into Microsoft Excel for analysis. Median and 3rd quartile KAP values were reported together with graphical illustrations. RESULTS: Data from 407 X-ray examinations were analysed. For the previously identified weight categories (5 to <15 kg, 15 to <30 kg, 30 to <50 kg, 50 to 80 kg), TVs for the chest were 0.10, 0.19, 0.37 and 0.53 dGy.cm2, respectively. For the abdomen 0.39, 1.04, 3.51 and 4.05 dGy.cm2 and for the pelvis 0.43, 0.87, 3.50 and 7.58 dGy.cm2. Between X-ray rooms TVs varied against the institutional TVs by -60 to 119 % (chest), -50 to 103 % (abdomen) and -14 and 24 %% (pelvis). CONCLUSION: TVs in this study follow established trends with patient weight and examination type and are comparable with published literature. Variations do exist between individual examination rooms and reasons are multifactorial. Given that age and size do not perfectly correlate further work should be undertaken around weight-based TVs/DRLs in the paediatric setting.

Impact of dental imaging on pregnant women and recommendations for fetal radiation safety: A systematic review.

Purpose: This study was conducted to investigate the safety of dental imaging in pregnant women with respect to fetal health. Materials and Methods: Searches were conducted of the PubMed, Scopus, and Web of Science databases in May 2023. The inclusion criteria encompassed cross-sectional and longitudinal studies that focused on the analysis of diagnostic dental imaging in pregnant women, as well as studies utilizing phantoms to simulate imaging examinations. The exclusion criteria consisted of reviews, letters to the editor, book chapters, and abstracts from scientific conferences and seminars. Results: A total of 3,913 articles were identified. Based on a review of the titles and abstracts, 3,892 articles were excluded, leaving 21 articles remaining for full-text review. Of these, 18 were excluded, and 4 additional articles were included as cross-references. Ultimately, 7 articles underwent quantitative-qualitative analysis. Three retrospective studies were focused on pregnant women who underwent dental imaging procedures. The remaining 4 studies utilized female phantoms to simulate imaging examinations and represent the radiation doses absorbed by the uterus or thyroid. Conclusion: Few dental radiology studies have been conducted to determine the safe radiation threshold for pregnant women. Additionally, the reviewed articles did not provide numbers of dental examinations, by type, corresponding to this dose. Dental imaging examinations of pregnant women should not be restricted if clinically indicated. Ultimately, practitioners must be able to justify the examination and should adhere to the "as low as diagnostically acceptable, being indication-oriented and patient-specific" (ALADAIP) principle of radioprotection.

Awareness of Radiation Hazards and Knowledge About Radiation Protection Among Medical Students at the Northern Border University, Arar.

Studies have shown that medical students and doctors are not well equipped with knowledge of radiation hazards and their protection. This lack of knowledge may cause harm to patients and healthcare professionals. Objectives To compare the awareness of radiation hazards and knowledge about radiation protection among medical students at Northern Border University, Arar, Saudi Arabia, with and without prior teaching. Methods and materials This cross-sectional study was carried out among medical students from clinical years at Northern Border University, Arar, Saudi Arabia, from May 1st, 2023, to June 30th, 2023. Their consents were taken. Then they were randomly sorted into two groups. One group was given a radiation safety short course, and then they answered a questionnaire. The other group filled out the questionnaire without prior instruction, and analysis was done. The outcome of this study was quantified based on the score calculated after participants filled out the questionnaire. Results The mean score of students who didn't attend the radiology course was 3.38±1.8, while the score of students who attended the radiology course was 7.87±1.4 (p<0.001). Radiology course attendance showed a significant association with knowledge and awareness scores. Conclusions The average knowledge of medical students regarding radiation protection and hazards is quite poor. This lack of understanding could potentially lead to increased risks for both patients and healthcare professionals. The knowledge about radiation hazards and protection is increased in students who attended a short radiology course. We recommend implementing comprehensive educational programs that focus on radiation hazards and protection for medical students.

Age-based diagnostic reference levels and achievable doses for paediatric CT: a survey in Shanghai, China.

Computed tomography (CT) is extensively utilised in medical diagnostics due to its notable radiographic superiority. However, the cancer risk associated with CT examinations, particularly in children, is of significant concern. The assessment of cancer risk relies on the radiation dose to examinees. Diagnostic reference levels (DRLs) and achievable doses (ADs) were used to assess the level of radiation dose in CT examinations widely. Although the national DRLs of paediatric CT have been explored in China, few local DRLs at the city level have been assessed. To set up the local DRLs and ADs of paediatric CT, we investigated the radiation dose level for paediatric CT in Shanghai. In this survey, a total of 3061 paediatric CT examinations underwent in Shanghai in 2022 were selected by stratified sampling, and the dose levels in terms of volume CT dose index (CTDIvol) and the dose-length product (DLP) were analysed by 4 age groups. The DRLs and ADs were set at the 75th and 50th percentile of the distribution and compared with the previous studies at home and abroad. The survey results revealed that, for head scan, the DRLs of CTDIvolwere from 25 to 46 mGy, and the levels of DLP were from 340 to 663 mGy·cm. For chest, the DRLs of CTDIvolwere from 2.2 to 8.3 mGy, and the levels of DLP were from 42 to 223 mGy·cm. For abdomen, the DRLs of CTDIvolwere from 6.3 to 16 mGy, and the levels of DLP were from 181 to 557 mGy·cm. The ADs were about 60% lower than their corresponding DRLs. The levels of radiation doses in children-based hospitals were higher than those in other medical institutions (P< 0.001). In conclusion, there was still potential for reducing radiation dose of paediatric CT, emphasising the urgent need for optimising paediatric CT dose in Shanghai.

Radiation protection in a cohort of healthcare workers: knowledge, attitude, practices, feelings and IR-exposure in French hospitals.

The number of healthcare workers occupationally exposed to ionizing radiation (IR) is increasing every year. As health effects from exposure to low doses IR have been reported, radiation protection (RP) in the context of occupational activities is a major concern. This study aims to assess the compliance of healthcare workers with RP policies, according to their registered cumulative dose, profession, and perception of radiation self-exposure and associated risk. Every healthcare worker from one of the participating hospitals in France with at least one dosimetric record for each year 2009, 2014, and 2019 in the SISERI registry was included and invited to complete an online questionnaire including information on the worker's occupational exposure, perception of IR-exposure risk and RP general knowledge. Hp(10) doses were provided by the SISERI system. Multivariate logistic regressions were used. Dosimeter wearing and RP practices compliance were strongly associated with 'feeling of being IR-exposed' (OR = 3.69, CI95% 2.04-6.66; OR = 4.60, CI95% 2.28-9.30, respectively). However, none of these factors was associated with RP training courses attendance. The main reason given for non-compliance is unsuitability or insufficient numbers of RP devices. This study provided useful information for RP policies. Making exposed workers aware of their own IR-exposure seems to be a key element to address in RP training courses. This type of questionnaire should be introduced into larger epidemiological studies. Dosimeter wearing and RP practices compliance are associated to feeling being IR-exposed. RP training courses should reinforce workers' awareness of their exposure to IR.