What is already known on this topic?:Healthcare workers in 131I treatment facilities face potential occupational internal exposure through inhalation of volatile radioiodine, in addition to external exposure. What is added by this report?:This study presents the first comprehensive national monitoring data on internal exposure among Chinese nuclear medicine (NM) workers. Approximately one-fifth of personnel working at radioiodine treatment sites showed detectable levels of 131I in their thyroid tissue. What are the implications for public health practice?:These findings provide essential baseline data for enhancing radiation protection protocols in NM facilities and optimizing national internal exposure monitoring.

ABSTRACT:Considering workers in interventional radiology occupationally exposed to relatively higher radiation dose, it is imperative to reasonably and reliably assess the occupational exposure of these workers. This paper presents a method to evaluate the occupational exposure to the interventional radiology workers monitored by using two personal dosimeters, based on data from 115,997 workers collected by the Chinese Registry of Radiation Workers in China during the period 2015-2021. It was observed that only 17.7% (20,572 in 115,997) of interventional radiology staff had a meaningful measurable result. The scatter plot of Hp (10) over - Hp (10) under vs. Hp (10) over was obtained to classify between the proper use group and misuse group. In addition, it was found that the effective dose calculated using the single-dosimeter approach proposed by Martin and Magee was close to those obtained using two other double-dosimeter approaches. Furthermore, the Swiss ordinance algorithm was chosen to assess the occupational exposure as a conservative estimation method. Meanwhile, it was also found that the average annual effective dose in tertiary hospitals is significantly higher than that in secondary hospitals in China ( Z = -2.491, p < 0.05/3 = 0.017). Based on these observations, rigorous surveillance, quality control measures, and better workload management are still necessary to correctly evaluate the occupational exposure of interventional radiology staff. Our results are expected to provide a feasible and accurate method for the evaluation of occupational radiation dose to interventional radiology staff wearing two personal dosimeters and contribute to effective prevention and control of radiation health risks.

Purpose The aim of this study was to evaluate the radiation level of a ZAP-X self-shielding system by comparing it with the requirements of the Chinese radiation protection standards and to provide a practical solution for the operation of ZAP-X in China.Methods Under the maximum workload of the ZAP-X system, the weekly radiation dose and the instantaneous dose rate (IDR) outside the safety perimeter of the ZAP-X system were compared to the requirements of relevant standards.Results The maximum weekly and annual dose equivalents, derived from the IDRs and accumulative doses, were as follows:1.99 mu Sv/week and 0.10 mSv/year, and 3.47 mu Sv/week and 0.17 mSv/year, respectively.Conclusion The radiation levels around the ZAP-X system meet the requirements of the weekly and annual dose constraints in relevant Chinese standards. The IDRs generated by the ZAP-X system do not meet the requirements of the existing radiation protection standards. A viable solution is to adjust the safety perimeter to comply with existing standards.

PURPOSE:To create and evaluate a three-dimensional (3D) Prompt-nnUnet module that utilizes the prompts-based model combined with 3D nnUnet for producing the rapid and consistent autosegmentation of high-risk clinical target volume (HR CTV) and organ at risk (OAR) in high-dose-rate brachytherapy (HDR BT) for patients with postoperative endometrial carcinoma (EC). METHODS AND MATERIALS:On two experimental batches, a total of 321 computed tomography (CT) scans were obtained for HR CTV segmentation from 321 patients with EC, and 125 CT scans for OARs segmentation from 125 patients. The numbers of training/validation/test were 257/32/32 and 87/13/25 for HR CTV and OARs respectively. A novel comparison of the deep learning neural network 3D Prompt-nnUnet and 3D nnUnet was applied for HR CTV and OARs segmentation. Three-fold cross validation and several quantitative metrics were employed, including Dice similarity coefficient (DSC), Hausdorff distance (HD), 95th percentile of Hausdorff distance (HD95%), and intersection over union (IoU). RESULTS:The Prompt-nnUnet included two forms of parameters Predict-Prompt (PP) and Label-Prompt (LP), with the LP performing most similarly to the experienced radiation oncologist and outperforming the less experienced ones. During the testing phase, the mean DSC values for the LP were 0.96 ± 0.02, 0.91 ± 0.02, and 0.83 ± 0.07 for HR CTV, rectum and urethra, respectively. The mean HD values (mm) were 2.73 ± 0.95, 8.18 ± 4.84, and 2.11 ± 0.50, respectively. The mean HD95% values (mm) were 1.66 ± 1.11, 3.07 ± 0.94, and 1.35 ± 0.55, respectively. The mean IoUs were 0.92 ± 0.04, 0.84 ± 0.03, and 0.71 ± 0.09, respectively. A delineation time < 2.35 s per structure in the new model was observed, which was available to save clinician time. CONCLUSION:The Prompt-nnUnet architecture, particularly the LP, was highly consistent with ground truth (GT) in HR CTV or OAR autosegmentation, reducing interobserver variability and shortening treatment time.

Radon is a naturally occurring radioactive gas that exists everywhere in our living or working environments.1 Radon and its decay products are considered to be the second leading causes of lung cancer in tobacco smokers and the leading cause in nonsmokers.2 Therefore,accurately measuring radon concentrations in the environment,understanding its behaviours,and implementing measures to mitigate radon are important for protecting the human health.

Objective To evaluate the health-care level (HCL), one of the most extensively used indicators to assess the level of medical exposure, and its influencing factors in China. Methods Based on the data from the China Statistical Yearbook of the National Bureau of Statistics and other public documents, HCL was calculated in terms of the number of physicians per head of population throughout the country. Multiple linear regression was used to analyze the association of HCL with main socioeconomic factors, including population size, area, number of administrative divisions and gross domestic product (GDP). Results Since 2015, there has been at least one physician for every 1,000 people in China on average. However, by 2019, there has yet been one physician for more than 1,000 people in each of two provinces. By 2020, there was at least one physician for every 1,000 people across all 31 provincial-level administrative districts (provinces). The population size and GDP were the influencing factors on HCL, with correlation coefficients of 0.416 and −0.583, respectively. Furthermore, a moderate correlation was found between HCL and the frequency of medical exposure (FME) to ionizing radiation (r ​= ​−0.620, P ​= ​0.028). Conclusion There has been at least one physician for every 1,000 people since 2015, but there are great differences between various provinces. HCL as an indicator to evaluate level of medical exposure is warranted further research in China.

To report the results of a dose survey conducted across 31 provinces in mainland China from 2017 to 2018 and to analyse the dose level to determine the national diagnostic reference levels (DRLs) for paediatric CT procedures. At least ten patients for each age group (0– < 1, 1– < 5, 5– < 10, 10– < 15 years) and each procedure (head, chest and abdomen) for each CT scanner were selected from four to eight hospitals in each province. The dose information (CTDIvol and DLP) was collected from the HIS or RIS-PACS systems. The median values in each CT scanner were considered the representative dose values for the paediatric patients in CT scanning. The national DRLs were estimated based on the 75th percentile distribution of the median values. A total of 24,395 patients and 319 CT scanners were investigated across 262 hospitals. For paediatric CT scanning in 4 different age groups, the median (P50) and the 75th percentile (P75) of CTDIvol and DLP for each scanning procedure were calculated and reported. National DRLs were then proposed for each procedure and age group. The dose level of CT scanning for children in mainland China was reported for the first time. The DRLs for paediatric CT in the present study are similar to those in some Asian countries but higher than those in European countries. The paediatric CT is an extensively used tool in diagnosing paediatric disease; however, children are more sensitive to radiation. Establishing the diagnostic reference level of paediatric CT examination is necessary to reduce the dose of CT in children and promote the optimisation of medical exposure. • The DRLs for 3 paediatric CT procedures (head, chest and abdomen) and 4 age groups (0– < 1, 1– < 5, 5– < 10, 10– < 15 years) were proposed in mainland China first time. • The examination parameter and dose for children need to be further optimised in China, especially to lower the tube voltage in paediatric CT.

Objective.To develop and evaluate a 3D Prompt-ResUNet module that utilized the prompt-based model combined with 3D nnUNet for rapid and consistent autosegmentation of high-risk clinical target volume (HRCTV) and organ at risk (OAR) in high-dose-rate brachytherapy for cervical cancer patients.Approach.We used 73 computed tomography scans and 62 magnetic resonance imaging scans from 135 (103 for training, 16 for validation, and 16 for testing) cervical cancer patients across two hospitals for HRCTV and OAR segmentation. A novel comparison of the deep learning neural networks 3D Prompt-ResUNet, nnUNet, and segment anything model-Med3D was applied for the segmentation. Evaluation was conducted in two parts: geometric and clinical assessments. Quantitative metrics included the Dice similarity coefficient (DSC), 95th percentile Hausdorff distance (HD95%), Jaccard index (JI), and Matthews correlation coefficient (MCC). Clinical evaluation involved interobserver comparison, 4-grade expert scoring, and a double-blinded Turing test.Main results.The Prompt-ResUNet model performed most similarly to experienced radiation oncologists, outperforming less experienced ones. During testing, the DSC, HD95% (mm), JI, and MCC value (mean ± SD) for HRCTV were 0.92 ± 0.03, 2.91 ± 0.69, 0.85 ± 0.04, and 0.92 ± 0.02, respectively. For the bladder, these values were 0.93 ± 0.05, 3.07 ± 1.05, 0.87 ± 0.08, and 0.93 ± 0.05, respectively. For the rectum, they were 0.87 ± 0.03, 3.54 ± 1.46, 0.78 ± 0.05, and 0.87 ± 0.03, respectively. For the sigmoid, they were 0.76 ± 0.11, 7.54 ± 5.54, 0.63 ± 0.14, and 0.78 ± 0.09, respectively. The Prompt-ResUNet achieved a clinical viability score of at least 2 in all evaluation cases (100%) for both HRCTV and bladder and exceeded the 30% positive rate benchmark for all evaluated structures in the Turing test.Significance.The Prompt-ResUNet architecture demonstrated high consistency with ground truth in autosegmentation of HRCTV and OARs, reducing interobserver variability and shortening treatment times.

ABSTRACT:The primary purpose of this study was to report the mean glandular doses and to determine the national diagnostic reference levels for digital mammography based on data between 2016 and 2018 in China. The data from 19,076 mammograms (4,769 examinations) by random sampling from 118 digital mammography systems were compiled. Exposure factors included age, compressed breast thickness, kVp, mAs, target/filter combination, entrance surface air kerma, and mean glandular doses, which were retrospectively surveyed and recorded from the monitor. The national diagnostic reference levels (75th percentiles) in mean glandular dose were calculated across median value obtained for all included data and stratified to specific compressed breast thickness ranges. The patients' ages ranged from 22 to 88 y, with a median age of 45. The applied voltage and output medians were 28 kVp and 75.1 mAs for all exposure, respectively. The median CBTs were 45 mm and 48 mm for craniocaudal views and mediolateral oblique views, and the corresponding median mean glandular doses were 1.32 mGy and 1.40 mGy, respectively. The national diagnostic reference level at compressed breast thickness of 40-50 mm was 1.67 mGy for CC views and 1.71 mGy for MLO views. The median mean glandular doses varied significantly and increased with compressed breast thickness, demonstrating the necessity of establishing DRL according to breast thickness and optimizing the clinic's digital mammography practice in China.

A retrospective analysis of occupational exposure to ionizing radiation from medical uses and industrial uses in the three provinces of Central China from 2000 to 2021 was conducted. The average annual effective dose in medical uses and industrial uses decreased from 2.042 mSv and 2.334 mSv in 2000–2002 to 0.476 mSv and 0.371 mSv in 2021 respectively; the fraction of monitored workers receiving annual dose not exceeding 1 mSv increased from 60.78% and 74.45% in 2000–2002 to 94.20% and 96.85% in 2021 respectively, while receiving annual doses exceeding 20 mSv declined from 1.35% and 1.91% in 2000–2002 to 0.18% and 0.03% in 2021 respectively. The average annual effective dose and NR20 in the period 2000–2021 were relatively high in professional public health institutions (0.955 mSv and 0.004) and hospitals (0.815 mSv and 0.004). In 2021, the average annual effective dose to monitored workers in different occupational categories in medical uses in the three provinces of Central China were in the range of 0.199–0.692 mSv, with interventional radiology received the highest dose and NR20 (0.692 mSv and 0.005); the average annual effective dose ranged from 0.161 to 0.493 mSv in industrial uses, with industrial radiography received the highest dose and NR20 (0.493 mSv and 0.001). Occupational exposure in medical uses and industrial uses declined obviously in Central China, and the groups receiving higher doses are the radiation workers working in hospitals and professional public health institutions, or engaged in interventional radiology, nuclear medicine and industrial radiography, warranting more effective radiation protection measures.

Objective:We aimed to analyze the current indoor radon level and estimate the population risk of radon-induced lung cancer in urban areas of China. Methods:Using the passive monitoring method, a new survey on indoor radon concentrations was conducted in 2,875 dwellings across 31 provincial capital cities in Chinese mainland from 2018 to 2023. The attributable risk of lung cancer induced by indoor radon exposure was estimated based on the risk assessment model. Results:The arithmetic mean (AM) and geometric mean (GM) of indoor radon concentrations were 65 Bq/m³ and 55 Bq/m³, respectively, with 13.6% of measured dwellings exceeding 100 Bq/m³ and 0.6% exceeding 300 Bq/m³. The estimated number of lung cancer deaths induced by indoor radon exposure was 150,795, accounting for 20.30% (95% CI: 20.21%-20.49%) of the lung cancer death toll. Conclusion:This study provided the most recent data on national indoor radon levels in urban areas and the attributable risk of lung cancer. These results served as an important foundation for further research on the disease burden of indoor radon exposure and radon mitigation efforts.

To investigate the levels of I-131 activity in thyroid of workers at the place of radioiodine therapy and their main influential factors in China, 341 workers at 38 hospitals performing radioiodine therapy procedure in five provinces were recruited to be measured in 2021. A hand-held gamma spectrometer with NaI(Tl) probe was plastered to the thyroids and thighs of the subjects during the measurement, and each measurement time was 120 s. The internal exposure dose was calculated, and the committed effective dose was estimated. In 86 (25.22%) of the 341 examined workers, I-131 thyroid activity was above minimum detectable activity (MDA, 26.6 Bq). The maximum activity was 4.9 x 10(3 )Bq. The detection results above MDA were at 22 (57.89%) different hospitals. The detectable rate for private hospitals (4.8%) was significantly lower than that for public hospitals (26.6%), P < 0.05. The detectable rate for hospitals in provincial capital cities (15.4%) was significantly lower than in nonprovincial capital cities (41.7%), P < 0.001. The detectable rate for hospitals engaged in I-131 therapy for thyroid cancer (31.2%) was significantly higher than only for hyperthyroidism (10.3%), P < 0.001. A total of 32 subjects' committed effective dose might exceed 1 mSv. Results indicated the I-131 activity in the thyroid of workers at the place of radioiodine varied considerably in China, and mainly related to ownership, location and therapy program of the hospitals.

Objective To obtain the medical exposure frequency data of residents through a questionnaire survey on mobile phone networks in the community, and to analyze the main influencing factors. Methods A snowball sampling method was used to expand the sampling from medical staff in a county hospital to the community. The questionnaire included personal information such as occupation category, type of medical insurance, and education level as well as basic radiationrelated knowledge and medical exposure type and frequency of respondents received in 2021. A logistic regression model was used to analyze the influencing factors of medical exposure. Results A total of 223 respondents were investigated, and12.56% of them received radiological diagnosis and radiotherapy in 2021. The proportion of males receiving medical exposure was significantly higher than that of females（19.64% vs 10.18%）. The likelihood of the person receiving medical exposure increased considerably with age, with the proportion of residents receiving medical exposure at 20, 30, 40, and 50 years of age being 6.25%, 7.95%, 19.23%, and 33.33%, respectively. Of persons who received medical exposure, 57.14% underwent CT scans. Persons participating in the new rural cooperative medical system were likely less to receive radiological diagnosis and radiotherapy than urban workers and residents（OR = 0.55, CI:0.13-2.23, P ＞ 0.05）. Conclusion Questionnaire survey in the community can obtain more information about the medical exposure of residents, and age and type of medical insurance are important factors affecting the frequency of medical exposure.

The radioactive safety of drinking water has attracted increasing public concern. The newly issued Standards for Drinking Water Quality (GB5749-2022) in China has revised the radiological parameters. This article provides an overview of the main sources, levels of radionuclides in drinking water, and summarized the individual doses criterion and adverse health effects associated with exposure of the public to radionuclides from drinking-water. It analyzes and discusses the relevant revision content of radiological parameters, including the guidance values for screening gross α and gross β, subtracting the contribution of potassium-40 from gross β activity when the gross β activity concentration exceeds the screening level, and the basis for establishing the limit values of reference indices uranium and radium-226. Specific implementation and evaluation suggestions are also proposed.

In recent years, the diagnostic radiology, especially CT scanning, has a rapidly increased frequency in our country, becoming the largest artificial radiation source to the average individual doses to the population. In clinical diagnosis and treatment activities, the examined patients and individuals may undergo multiple procedures and multiple frequencies of medical imaging in a short period of time and receive high cumulative radiation doses even exceeding 50 or 100 mSv in a single day, posing a potential risk to their health. Therefore, it is necessary to carry out statistical analysis and management of diagnostic radiation dose information to minimize the probability of excessive dose and associated radiation risk. In this paper, the international cognition of radiation risks in diagnostic radiology, diagnostic equipment and medical imaging frequency, radiation dose and its management status are described. Four countermeasures for radiation dose management are put forward to provide reference for further improving radiation protection in clinical practice.

In China, according to statistics about underground non-uranium mine radon levels, 15% exceed the national standard intervention level of 1000 Bq/m(3), and some mines may exceed 10,000 Bq/m(3). The relationship between radon exposure in underground miners and lung cancer has already been established, but the mechanisms and biological processes underlying it are poorly understood. In order to identify the genome-wide DNA methylation profile associated with long-term radon exposure, we performed the Infinium Human Methylation 850 K BeadChip measurement in whole blood samples obtained from 15 underground non-uranium miners and 10 matched aboveground control workers. Radon concentrations in the air of workplaces and living environments were measured by CR-39 radon detectors, and annual effective doses were calculated using the detection data. Under the high radon concentration with an average value of 12,700 Bq center dot m(-3), a total of 165 significant differentially methylated positions (127 hypermethylated sites and 38 hypomethylated sites) annotated to 71 genes were identified in underground miners (|Delta beta| >= 0.10, p < 0.05), and the average DNA methylation level of 165 DMPs was significantly higher than that of the control workers. Most DMPs were found on chromosome 1, and approximately one-quarter of them were located in genomic promoter regions. Through bioinformatics analysis and pyrosequencing validation, five candidate genes differentially methylated by radon, including TIMP2, EMP2, CPT1B, AMD1 and SLC43A2 were identified. GO and KEGG analysis implicated that long term radon exposure could induce the lung cancer related biological processes such as cell adhesion and cellular polarity maintenance. Our study provides evidence for the alterations of genome-wide DNA methylation profiles induced by long-term high level radon exposure, and new insights into searching for carcinogenic biomarkers of high radon exposure in future studies.

建立核电站的目的是为了满足日益增长的能源需求,不幸的是历史上发生过5次重大的核事故,给个人和社会带来了多样且持久的影响,广为人知的健康效应是大剂量导致的组织反应和低剂量辐射致癌效应.近年对核电站事故受影响地区的成年居民、有年轻孩子的母亲以及受高剂量照射的清理/去污人员的研究表明,核事故发生后对这类人群产生了长期心理健康影响,本文对这些人群的心理影响进行了综述.

Objective:To evaluate the radiation shielding performance for a novel self-shielded ZAP-X radiotherapy system used for intra-cranial and neck treatments. The present evaluation was performed according to the relevant Chinese national standards and the clinical placement of the radiotherapy system in an unshielded treatment room.Methods:The radiation source of the ZAP-X was a 3 MV linear accelerator. A total of 33 detection sites were selected surrounding the self-shielded system at 1.3, 2.3 and 3.3 m away from the periphery of the equipment. The maximum ambient dose equivalent rate in each irradiation condition was measured accordingly. A commonly used clinical treatment plan was selected to simulate the treatment process. During the delivery of this treatment plan, the cumulative doses of these 33 sites were measured, separately. The applicable current radiation protection standard for radiotherapy in China was chosen to evaluate the radiation shielding performance of the system.Results:According to the measurement result of the ambient dose equivalent rates along the aforementioned perimeter lines, a suggestion was put forward to redefine the existing 1 m controlled area by determining the distance at which the instantaneous dose rate of 10 μSv/h will not be exceeded. This is to meet the requirements of the Chinese standard GBZ 121-2020.Conclusions:According to the existing Chinese national radiation protection standards, the self-shielded radiotherapy system in the unshielded treatment room has the clinical applicability in China. But for such a novel self-shielded system, the corresponding performance testing and radiation protection standards shall be formulated.

Objective:To investigate and analyze the eye lens dose to interventional radiology workers in China from 2019 to 2021.Methods:The monitoring data on eye lens dose to interventional radiology workers from 31 province-level units during 2019-2021 were collected through the National Radiological Health Information Platform. The eye lens dose evaluation indicator was Hp(3), with each monitoring period of no more than 3 months. Kusall-Wallis H test was used for the comparison of multiple groups and pairwise. Results:A total of 6 643 interventional radiology workers were investigated from 2019 to 2021. The average annual eye lens dose was 1.03 mSv, with the median of 0.17 mSv and the maximum of 94.88 mSv. The annual eye lens dose to 59 workers exceeded 20 mSv. It was also found that the annual eye lens dose to the doctors in 2019 and 2020 was slightly higher than that to nurses (rank mean difference=118.29, 129.71, P<0.01), and the lens dose to interventional radiology workers who performed cardiac interventions in 2019 was higher than that to workers who performed peripheral vascular interventions (rank mean difference=46.52, P<0.05). Conclusions:The lens dose to interventional radiology workers is lower than the limits given in Chinese national standard currently in effect, but exceed the latest internationally recommended limit for a few ones. In order to protect the occupational health of interventional radiology workers, the monitoring of lens dose should be strengthened.

With the development of social economy and radiotherapy technique, proton/heavy ion radiotherapy has been applied widely to clinical practices. At present, there are at least 29 hospitals in China at various stages of planning, construction, commissioning or clinical operation of medical proton/heavy ion beam radiotherapy equipment. Compared with common radiotherapy accelerators used in conventional external beam radiotherapy, the proton/heavy ion therapy system has more stringent requirements for quality control so as to achieve an optimum therapeutic effect. In order to protect the health rights of patients undergoing radiotherapy, to facilitate the relevant administrative supervision departments to carry out standard-based approval and routine supervision and to promote the development of related medical undertakings, the standard for testing of quality control for medical proton/heavy ion beam radiotherapy equipment is drafted to fill the gap in this regard in China and even worldwide. The standard contains five indicators and corresponding testing methods for radiological protection and safety and 16 indicators for quality control of equipment performance. The standard is a mandatory standard and is based on the relevant Chinese legal requirements for the testing of radiotherapy equipment, so all the indicators listed in the standard shall be tested. During the drafting of the standard, the opinions from hospitals that are currently using proton/heavy ion medical accelerators for radiotherapy purpose and from the related equipment manufacturers were taken into account. The draft standard was revised with reference to these opinions and the feasibility of the related quality control requirements. The official version of the standard was released on March 7, 2023, and implementation is scheduled to begin on March 1, 2024.