Objective To systematically analyze the medical radiation exposure levels in a district of Ningbo City and to provide a scientific basis for the reasonable and effective control of medical radiation exposure. Methods Based on the radiological diagnosis frequency and dose information system, basic medical radiation exposure data were collected, such as radiation doses received by patients in various X-ray diagnostic examinations, from all 13 public medical institutions in a district of Ningbo City from January 1 to December 31, 2020. The data were analyzed for the percentage and collective effective dose of various diagnostic examinations, the distribution of examinations by sex and age, and the number of patients undergoing two or more examinations and their cumulative doses within multiple time intervals. Results Among medical X-ray diagnostic examinations in the district, the percentages of CT examination and routine photography examination were 50.88% and 47.93%, respectively, and the collective effective dose of CT examination accounted for 97.75%. By age and sex, the frequency of examination was the highest in the age group of 45-54 years, and the frequency of examination in the male was higher than that in the female before age 55. The annual effective dose for two patients exceeded 100 mSv. Conclusion In this study, CT examination accounted for up to 50.88% of all medical X-ray diagnostic examinations, and contributed 97.75% of the collective effective dose, highlighting the need for particular attention to the justification of medical radiation exposure from CT.

Objective To evaluate the application of three deep learning algorithms in automatic segmentation of clinical target volumes (CTVs) in high-dose-rate brachytherapy after surgery for endometrial carcinoma. Methods A dataset comprising computed tomography scans from 306 post-surgery patients with endometrial carcinoma was divided into three subsets: 246 cases for training, 30 cases for validation, and 30 cases for testing. Three deep convolutional neural network models, 3D U-Net, 3D Res U-Net, and V-Net, were compared for CTV segmentation. Several commonly used quantitative metrics were employed, i.e., Dice similarity coefficient, Hausdorff distance, 95th percentile of Hausdorff distance, and Intersection over Union. Results During the testing phase, CTV segmentation with 3D U-Net, 3D Res U-Net, and V-Net showed a mean Dice similarity coefficient of 0.90 ± 0.07, 0.95 ± 0.06, and 0.95 ± 0.06, a mean Hausdorff distance of 2.51 ± 1.70, 0.96 ± 1.01, and 0.98 ± 0.95 mm, a mean 95th percentile of Hausdorff distance of 1.33 ± 1.02, 0.65 ± 0.91, and 0.40 ± 0.72 mm, and a mean Intersection over Union of 0.85 ± 0.11, 0.91 ± 0.09, and 0.92 ± 0.09, respectively. Segmentation based on V-Net was similarly to that performed by experienced radiation oncologists. The CTV segmentation time was < 3.2 s, which could save the work time of clinicians. Conclusion V-Net is better than other models in CTV segmentation as indicated by quantitative metrics and clinician assessment. Additionally, the method is highly consistent with the ground truth, reducing inter-doctor variability and treatment time.

Objective To study the unqualified items in the reported quality control tests of linear accelerators, analyze the issues in quality control tests, and propose the key points and development directions for accelerator quality control test in China. Methods A literature review was conducted using the CNKI database to analyze the qualified rates of test items and the issues in quality control tests. Results In the literature on the quality control tests of linear accelerators, except for a few provinces where the qualified rates of all test items were 100%, unqualified items were reported in most of the literature. There were unqualified items related to X-ray and electron beam in different reports. Error of dose indication was the unqualified item with the highest occurrence rate in X-ray test, and the item with the lowest qualified rates in X-ray and electron beam tests. The lowest qualified rate of X-ray dose indication error was 73.5% in 2016, and the lowest qualified rate of electron beam dose indication error was 46.2% in 2017. Conclusion Tests should be carried out strictly according to the items and intervals specified by the quality control test standards. Hospitals, radiation health technology service institutions, and health administrative departments should each fulfill their respective responsibilities, work together, and place emphasis on ensuring effective quality control tests of linear accelerators to further enhance the overall quality control standards for these devices.

Objective:To analyze the eye lens dose and annual effective dose to interventional radiation workers in some hospitals of Xinxiang city from 2020 to 2022, and to ascertain the dose to interventional radiation workers.Methods:By using TLDs, the eye lens dose Hp(3) and annual effective dose Hp(10) were monitored for three consecutive years in six hospitals in Xinxiang city. The lens doses and annual effective doses to intervention radiation workers in different years in different-level hospitals and departments were analyzed. Results:From 2020 to 2022, a total of 117 people were monitored. The left eye lens dose range was 0.12-164.24 mSv, and the right eye lens dose range was 0.07-51.64 mSv. The average annual dose was 8.56 mSv for left eye lens and 4.49 mSv for right eye lens The average annual dose distribution in the MDL-5 mSv range for the left and right eye lens was 60.68% and 73.50%, respectively. 9.41% (11 people) of the left eye lens doses exceeded 20 mSv. The annual effective doses range was 0.11-31.27 mSv, with average annual dose of 2.56 mSv. The proportion of average annual effective doses mainly distributed in the range of MDL to 1.25 mSv was 52.14%, with 2.56% annual effective dose exceeding 20 mSv. There was no significant difference in left and right eye lens dose and annual effective dose between the tertiary hospitals and the secondary hospitals in three years ( P>0.05). Compared with different departments, the cumulative per capita dose in three years was statistically significant (left eye H=11.42, right eye H=13.72, annual effective dose H=25.94, P<0.05). The lens dose and annual effective dose in neurology department were lower than those in cardiology department and comprehensive intervention department ( Zcardiology department=-3.33, -3.78, -4.83, P<0.05; Zcomprehensive intervention department=-2.71, -2.63, -4.39, P<0.05). Conclusions:Most of the annual equivalent dose and annual effective dose to eye lens of the interventional radiation workers in Xinxiang city meet the national limits, but some of them have higher doses and exceed the national limits. It is suggested that the routine and continuous monitoring of eye lens doses to interventional radiologists should be strengthened while routine monitoring of annual effective dose, and attention should be paid to the eye lens and annual effective dose to interventional radiologists in secondary hospitals to improve the awareness of protection.

Pregnancy with autoimmune diseases is a challenging area that involves multidisciplinary management of immunology, rheumatology, and obstetrics. During pregnancy, the maternal immune system dynamically regulates the balance between maintaining immune tolerance to the fetus and autoimmune. However, for women with common systemic autoimmune diseases such as systemic lupus erythematosus, antiphospholipid syndrome, and rheumatoid arthritis, this balance can be upset, leading to exacerbation or recurrence of the disease and significantly increasing the risk of pregnancy complications. This paper describes the adaptive changes of the immune system during pregnancy and the effects of systemic autoimmune diseases on pregnancy outcomes, proposes multidisciplinary management strategies and challenges in perinatal pregnancy, and aims to provide references for optimizing clinical practice and improving pregnancy outcomes.

Objective To analyze the factors influencing the levels of occupational exposure in medical radiation workers in China, and to provide a scientific basis for determining the key points of radiation protection in the medical sector. Methods The individual monitoring data on occupational external exposure in medical radiation workers in 2021 were collected from the “National Individual Dose Registry”. The Chi-squared test and logistic regression were used to analyze the factors influencing the levels of occupational exposure in medical radiation workers. Results The Chi-squared test showed that gender, occupational category, medical institution category, region, number of radiation workers per thousand population, and regional per capita GDP were significantly associated with occupational exposure in medical radiation workers exceeding the annual effective dose of 5 mSv and an annual effective dose limit of 20 mSv (χ² = 21.456−262.329, 7.601−78.650, P < 0.05). The logistic regression analysis further showed that gender, occupational category, region, and number of radiation workers per thousand population were factors influencing the occupational exposure in medical radiation workers exceeding the annual effective dose of 5 mSv (χ² = 14.621−170.857, P < 0.05); gender, occupational category, region, and regional per capita GDP were factors influencing the occupational exposure in medical radiation workers exceeding the annual effective dose of 20 mSv (χ² = 5.401−48.709, P < 0.05). Conclusion Male radiation workers in interventional radiology and in central China have high risks of exceeding annual effective doses of 5 and 20 mSv. Moreover, high number of radiation workers per thousand population and regional per capita GDP are associated with low risks. Medical institutions should maintain a sufficient number of radiation workers and strengthen training on radiation protection knowledge for male and interventional radiology workers to enhance their radiation protection awareness. Investigation of the factors contributing to the high occupational exposure in central China should be intensified, and targeted effective measures should be conducted to reduce the occupational exposure in medical radiation workers.

Since the implementation of the Measures for the Management of Radiation Workers’ Occupational Health in November 2007, it has played an extremely important role in protecting the occupational health of radiation workers. There are more than 700 000 radiation workers in about 100 000 workplaces with potential radiation exposure, as well as a large number of miners exposed to high levels of radon. As the radiation health monitoring project suggests, measures of occupational health management such as personal dose monitoring and occupational health examination of radiation workers have been widely implemented and achieved good results in the protection of radiation workers. However, the risks of chromosomal aberration and specific turbidity of the eye lens of radiation workers have increased in high-risk positions such as interventional radiology, nuclear medicine, and industrial flaw detection. The control of high radon exposure in miners needs to be strengthened. It is necessary to adapt to the new situation in view of new challenges and actively promote the revision of the Measures for the Management of Radiation Workers’ Occupational Health, so as to further improve the occupational health management of radiation workers in China.

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 develop an information system for testing radiological protection that can interface with National Radiation Health Information Platform/Medical Radiation Monitoring Subsystem and to improve the testing efficiency.Methods:Complying with the relevant national regulations and standards, the analysis was carried out of demand investigation and system modeling. An information system for testing radiological protection was established using B/S architecture, comprising three modules such as testing, audit and system management. The users at four levels were set of administrator, inspector, auditor and report issuer.Results:Based on test result, the developed information system has been shown to realize the informatization of the whole process from filling, auditing, issuing, issuing of the testing report to data uploading, with improved testing efficiency.Conclusions:The developed information system for testing radiological protection can improve the testing efficiency, and can be successfully interfaced with the National Radiation Health Information Platform/Medical Radiation Protection Monitoring Subsystem.

Objective:To ascertain the levels of individual doses to radiation workers arising from occupationally external exposure in China in 2017, with an aim to provide basic data and scientific basis for prevention and control of occupational radiation sickness.Methods:Data on individual doses to monitored workers engaged in medical and industrial applications of radiation sources were collected through National Individual Dose Registry, with statistical analysis being carried out using Kruskal-Wallis H test, Mann-Whitney U test and Bonferroni method. Results:A total of 361 727 radiation workers were investigated in 2017, of which 81.6% was from medical application and 18.4% from industrial application, respectively. The average annual effective dose from medical and industrial applications were 0.353 and 0.270 mSv, respectively, with the former significantly higher than the latter ( Z=48.547, P<0.05). Furthermore, a statistically significant difference was seen in the average annual effective dose for each occupational category of medical application ( H=1 136.217, P<0.05), suggesting that the dose values for the monitored workers in nuclear medicine and interventional radiology were significantly higher than for other four medical categories ( Z=2.877-26.967, P<0.05). These dose values for the radiation workers was 0.361 mSv in tertiary hospitals, 0.397 mSv in secondary hospitals, and 0.308 mSv in primary and unrated hospitals, respectively. The dose values for the monitored workers in industrial radiography and well logging were significantly higher than for other five industrial categories of industrial applications ( Z=4.172-36.908, P<0.05). Conclusions:The average annual effective doses to the of monitored workers meet the relevant national standards. The exposure doses to the workers in nuclear medicine, interventional radiology, industrial radiography and well logging are relatively high. The necessary measures and devices for radiation protection should be further strengthened to reduce occupational exposure of workers.