Objective To evaluate the overall implementation of the WS 76-2020 standard in Anhui Province, China and identify and analyze the factors affecting the implementation of the standard, and to provide a basis for the effective implementation and revision of WS 76-2020. Methods According to the requirements of the Notice of the Department of Regulations in National Health Commission on the 2024 assessment of implementation of mandatory standards, an evaluation of radiological health standards was organized and conducted in Anhui Province. The evaluation involved the three dimensions of standard implementation status, technical content of the standards, and effectiveness of standard implementation, with subsequent data analysis. Results The total evaluation score for WS 76-2020 was 87.83 points, indicating that the standard effectively guided the quality control testing of medical X-ray diagnostic equipment. However, stability testing was either underutilized or not performed in practice. The qualified rate of X-ray diagnostic equipment in the province was 94.26%, with equipment performance issues identified as the leading contributor to non-qualified instances. Expert discussions highlighted recommendations particularly concerning the operability, applicability, and scientific rigor of the standard. Conclusion It is recommended to strengthen the dissemination and training for the standard, promote medical institutions to voluntarily conduct stability testing, provide supplementary clarifications or revisions for problematic clauses, and standardize quality control testing techniques for radiological diagnostic equipment.

Objective To track and evaluate the implementation and application of the occupational health standard Radiation shielding requirements for radiotherapy room—Part 4: Radiotherapy room of ²⁵²Cf neutron afterloading (GBZ/T 201.4-2015) by radiation health technical service agencies, medical institutions, health supervision agencies, and radiotherapy facility design units, and to provide a scientific basis for the further revision and implementation of this standard. Methods Following the Guideline for health standards tracking evaluation (WS/T 536-2017) and the project implementation plan, relevant practitioners were randomly selected for a questionnaire survey. The survey primarily focused on their awareness, standard training, application, and revision suggestions of GBZ/T 201.4-2015. The results were summarized and analyzed. Results A total of 168 evaluation questionnaires were collected from relevant practitioners in 28 provinces. Only 31.6% of the respondents reported being “well familiar” or “ familiar” with the standard, 27.4% of the respondents believed that the standard was widely used, and 45.2% of the respondents believed that the standard could meet the needs of their work. Only 14.9% of the respondents had received relevant training on the standard, more than half of the respondents had not applied the standard within the past 10 years, and 45.2% of the respondents believed that the standard "needs to be revised". Conclusion Due to the small number of californium-252 neutron afterloading radiotherapy devices in operation on the market, the overall awareness of the standard is low, suggesting that relevant authorities need to strengthen training and publicity of the standard, and that certain sections of the standard need to be revised or merged.

Objective:To investigate the current status of occupational internal exposure of nuclear medicine staff performing 131I treatment, and explore the related influence factors, so as to provide a basis for protection against internal exposures. Methods:A survey was conducted using cluster random sampling method to ascertain all the nuclear medicine staff involved in 131I treatment in nuclear medicine hospitals in Hubei province for the years 2021 to 2023. The in vitro monitoring mesurement was made of the 131I activity in thyroid by using portable gamma spectrometer, and the committed effective dose was estimated. Results:The positive detection rate of 131I in treatment staff was between 18.75% and 21.12%, with an average of 20.08%. The highest value found in cleaning and nursing staff in iodine therapy workplaces. The detection rate found in two hospitals were up to 75.61% and 64.71%, respectively. The detection rate was positive for the three consecutive years. There was no statistically significant difference in the committed effective dose between different treatment positions, and the level of internal exposure was lower than the external exposure arising from nuclear medicine practice. Factors affecting detection rate of 131I in thyroid included the amount of 131I used for treatment, and disorder type for treatment, 131I dose, use or otherwise of automated radiopharmaceutical dispenser, and ventilation in treatment rooms. Conclusions:Continuous attention should be paid to the internal exposure of nuclear medicine staff for use of 131I for treatment. Ventilation should be provided regularly, as required, to the 131I treatment rooms and active rooms and the staff should wear masks during the relevant working processes.

Objective:To investigate the current status of occupational internal exposure of nuclear medicine staff performing 131I treatment, and explore the related influence factors, so as to provide a basis for protection against internal exposures. Methods:A survey was conducted using cluster random sampling method to ascertain all the nuclear medicine staff involved in 131I treatment in nuclear medicine hospitals in Hubei province for the years 2021 to 2023. The in vitro monitoring mesurement was made of the 131I activity in thyroid by using portable gamma spectrometer, and the committed effective dose was estimated. Results:The positive detection rate of 131I in treatment staff was between 18.75% and 21.12%, with an average of 20.08%. The highest value found in cleaning and nursing staff in iodine therapy workplaces. The detection rate found in two hospitals were up to 75.61% and 64.71%, respectively. The detection rate was positive for the three consecutive years. There was no statistically significant difference in the committed effective dose between different treatment positions, and the level of internal exposure was lower than the external exposure arising from nuclear medicine practice. Factors affecting detection rate of 131I in thyroid included the amount of 131I used for treatment, and disorder type for treatment, 131I dose, use or otherwise of automated radiopharmaceutical dispenser, and ventilation in treatment rooms. Conclusions:Continuous attention should be paid to the internal exposure of nuclear medicine staff for use of 131I for treatment. Ventilation should be provided regularly, as required, to the 131I treatment rooms and active rooms and the staff should wear masks during the relevant working processes.

Objective To track and evaluate the implementation of the Radiation Shielding Requirements in Room of Radiotherapy Installations—Part 1: General Principle (GBZ/T 201.1–2007) among relevant personnel in medical radiation institutions, and to provide a scientific basis for revising the standard. Methods According to the Guidelines for Health Standards Tracking Evaluation (WS/T 536–2017) and the implementation protocol of standard evaluation, an online survey was conducted among 212 relevant workers from 146 medical radiation institutions across 18 provinces in China. The data were aggregated and analyzed with the use of Microsoft Excel 2010. Results A total of 215 questionnaires were returned, of which 212 were valid. Among the valid respondents, 77.8% believe that this standard is universally applied; 96.2% believe that this standard can meet work needs; 63.7% have participated in relevant training on this standard; 74.1% use this standard once or more per year; and 10.8% believe that this standard needs to be revised. Conclusion Medial radiation workers have a high rate of awareness of the basic information and content of the standard, but the understanding and application of the standard content need to be improved. We recommend that relevant departments further strengthen the promotion of and training on the standard, revise some content based on actual situation, and improve workers’ ability to use the standard.

Objective:To asscentain the 131I activity concentration in 131I treatment workplaces and to explore the method of estimating the internal dose to workers by air sampling and to analyze its influencing factors. Methods:Air sampling method was used to collect aerosols containing radioactivity in 10 randomly selected workplaces in Zhengzhou where 131I therapy was performed. Aactivity concentration of 131I in treatment workplace was measured for gamma emitters by gamma-ray spectrometry. The internal dose due to 131I inhalation was estimated based on measurement result and field investigation result. Results:The activity concentration of 131I in air samples from 19 subpacking rooms ranged from 0.087 to 570 Bq/m 3, with an average of (51.04 ± 128.58) Bq/m 3. Those from 11 wards ranged from 0.162 to 54.6 Bq/m 3, with an average of (7.97 ± 15.89) Bq/m 3. In terms of the work hours recommended by the national standard GBZ 129-2016 Specifications for individual monitoring of occupational internal exposure, the estimated annual effective dose to radiation workers due to the inhalation of 131I ranges from 0.002 to 10 mSv, with an average of (0.61 ± 1.80) mSv, below the dose limit specified in the national standards. Conclusions:The samples with high 131I activity concentration in nuclear medicine workplaces of 10 medical institutions selected in Zhengzhou are mostly distributed in tertiary class hospitals operating large amount of radionuclide with large numbers of thyroid cancer patients adimitted. The result ing internal dose to radiation workers cannot be ignored. Estimating the internal dose based on the measurement result of air samples has a large uncertainty.However, air sampling method can promptly detect radioactive contamination in case of abnormal events or accidents, providing early warning for workers to carry out dose measurement from external exposure and internal exposure assessment.

Objective:To investigate the conversion of low-energy CBCT images into high-energy CBCT images in clinical radiotherapy based on the deep learning method of U-Net network, in order to provide dual-energy CBCT images and reduce radiation dose.Methods:The CBCT image data of CIRS electron density phantom and CIRS head phantom at 80 and 140 kV were collected by the on-board CBCT in radiotherapy equipment. The dataset was divided into training set and test set according to 10∶1. The U-Net network was used to predict CBCT images at high energy (140 kV) from low-energy (80 kV) CBCT images. Four parameters, including mean absolute error (MAE), structural similarity index (SSIM), signal-to-noise ratio (SNR) and peak signal-to-noise ratio (PSNR) were used to quantitatively evaluate predicted high-energy CBCT images.Results:The overall structural difference between the predicted high-energy image and the real high-energy image was smaller (SSIM: 0.993 ±0.003). The noise of predicted high-energy image was lower (SNR: 15.33±4.06), but there was a loss of inter-tissue resolution. Predicted high-energy images had slightly lower average CT values than real high-energy images, with less difference in low-density tissues (<10 HU, P > 0.05) and greater differences in high-density tissues (<21 HU, t = -7.92, P < 0.05). Conclusions:High-energy CBCT images with high structural similarity can be obtained from energy CBCT images by using deep learning method. The predicted high energy CBCT images have the potential to be applied to clinical dual-energy CBCT imaging technology in radiotherapy.

Objective To analyze the process of intercomparison of national personal dose monitoring, evaluate the ability of personal dose monitoring, and ensure the accuracy and reliability of monitoring results in our laboratory. Methods In accordance with the intercomparison protocol for 2019—2021, an energy-discriminant thermoluminescence dosimeter was used for measurement at different doses. The uncertainty of measurement was evaluated and compared with the reference value. Results H_p(10) was measured for intercomparison in 2019—2021. In 2019, the single group performance difference was −0.02 to 0.02 and the comprehensive performance was 0.02. These values were 0.02-0.10 and 0.05 in 2020, and −0.02 to 0.02 and 0.01 in 2021. The intercomparison results were rated as excellent in the three consecutive years. Conclusion The personal dose monitoring system in our laboratory was in good condition, and the monitoring results were accurate and reliable. Improving the knowledge of personnel and cultivating a serious working attitude are important for intercomparison and personal dose monitoring.

Objective To preliminarily compare ⁶LiF-⁷LiF and CR39 in individual neutron dose monitoring, and to provide a reference for improving individual neutron dose monitoring. Methods According to the GBZ 128-2019, 26 radiation workers from 7 institutions received individual neutron dose monitoring with ⁶LiF-⁷LiF and CR39 at the same time. The monitoring results were analyzed. Results For most of the workers, the personal neutron dose equivalent H_p(10) was less than the minimum detectable level. The results with the two monitoring methods differed in 6 of 26 workers. Conclusion Both ⁶LiF-⁷LiF and CR39 monitoring methods can be used for individual neutron dose monitoring for radiation workers, but the difference between ⁶LiF-⁷LiF and CR39 (in threshold energy, energy response, etc.) should be considered so that different types of radiation workers receive appropriate individual neutron dose monitoring.

Objective To determine the current status of occupational internal exposure to ¹³¹I in the thyroid of nuclear medicine workers, to explore the influencing factors for internal exposure, and to provide a basis for the radiation safety management of nuclear medicine. Methods The cluster sampling method was used to select 162 workers practicing ¹³¹I treatment in 24 hospitals in Hubei Province, China. Thyroid ¹³¹I activity levels were measured in vitro using a portable γ-spectrometer, and the committed effective dose was estimated. Results The thyroid ¹³¹I activity detected in 13 (54.17%) hospitals was above the lower limit of detection of the instrument. Two hospitals had the highest detection rates, 62.50% and 61.90%; the difference was significant compared with the remaining 11 hospitals (P < 0.0001). Thyroid ¹³¹I was detected in 34 workers in total, with a detection rate of 20.99% and a mean activity of 179.09 ± 138.71 (6.02-589.74) Bq. The highest detection rates were found in cleaners and nurses, which were 35.71% and 33.33%, respectively, with no significant difference in detection rate between positions (least P > 0.08). The mean value of the committed effective dose was 0.68 ± 0.52 (0.02-2.22) mSv/a in the 34 workers. Conclusion The ¹³¹I consumption and workplace ventilation may be important factors affecting the level of internal exposure. It is important to strengthen the training of nuclear medicine workers on radioprotection and workflow management, as well as the regular monitoring of occupational internal exposure for ¹³¹I treatment-related workers.