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 understand the current status of radiation protection in animal diagnosis and treatment institutions in Hubei province, identify the problems present in current condition, provide suggestions for standardized pet radiation practice, so as to ensure the health of staff and the public.Methods:A thorough survey was conducted for all animal diagnosis and treatment institutions in Hubei province. The stratified random sampling method was used for 167 animal diagnosis and treatment institutions of 16 cities by using of questionnaire survey. The survey contents mainly included basic situation of the animal diagnosis and treatment institutions, the management of radiation protection, the personnel′s job exposure situation, the management of radiation workers, etc. Totally 68 of them were selected by cluster sampling for the detection of radiation levels outside the machine rooms.Results:73.83% of these institutions had the behavior that the animal owners participated in and assisted in the in-room operation. Personal dose monitoring rate was 61.68%, occupational health examination rate was 72.46%, and training rate on radiation protection knowledge was 70.06%. Of these 68 institutions, 89.71% had met radiation protection standard in their machine rooms.Conclusions:There are deficiencies in the radiation workplace and personnel management of animal institutions in Hubei province. The animal diagnosis and treatment institutions should strengthen the learning of radiation protection knowledge, enhance the health management and training of personnel. Relevant departments should make the radiation protection ability of the industry to be higher by improving the relevant standards and strengthening publicity and regulatory control.

Objective:To understand the current status of radiation protection in animal diagnosis and treatment institutions in Hubei province, identify the problems present in current condition, provide suggestions for standardized pet radiation practice, so as to ensure the health of staff and the public.Methods:A thorough survey was conducted for all animal diagnosis and treatment institutions in Hubei province. The stratified random sampling method was used for 167 animal diagnosis and treatment institutions of 16 cities by using of questionnaire survey. The survey contents mainly included basic situation of the animal diagnosis and treatment institutions, the management of radiation protection, the personnel′s job exposure situation, the management of radiation workers, etc. Totally 68 of them were selected by cluster sampling for the detection of radiation levels outside the machine rooms.Results:73.83% of these institutions had the behavior that the animal owners participated in and assisted in the in-room operation. Personal dose monitoring rate was 61.68%, occupational health examination rate was 72.46%, and training rate on radiation protection knowledge was 70.06%. Of these 68 institutions, 89.71% had met radiation protection standard in their machine rooms.Conclusions:There are deficiencies in the radiation workplace and personnel management of animal institutions in Hubei province. The animal diagnosis and treatment institutions should strengthen the learning of radiation protection knowledge, enhance the health management and training of personnel. Relevant departments should make the radiation protection ability of the industry to be higher by improving the relevant standards and strengthening publicity and regulatory control.

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.

Objective To explore the quality control results of Digital Diagnost digital radiography (DR), and also to analyze the differences in signal transfer characteristics (STP) of DR from different manufacturers, in order to provide a reference for quality control of testers and daily supervision of administrative staff. Methods According to WS 76—2020 “Specification for testing of quality control in medical X-ray diagnostic equipment”, the test items such as automatic exposure control (AEC) repeatability, AEC response, detector dose indication (DDI), STP, high-contrast resolution, and low-contrast resolution of Digital Diagnost DR were qualitatively controlled, and several common DRs on the market were selected to analyze their STP functional relationships. Results The baseline values of DDI, high-contrast resolution, and low-contrast resolution of Digital Diagnost DR were 19733, 2.8 Lp/mm, and H5 of image central pixel value, respectively; the quality control results of other test items met the requirements of WS 76—2020. The STP functional relationships of common DRs were mainly linear and logarithmic, but different models of DR from the same manufacturer might also have different STP functional relationships. Conclusion When testing some special test items of DR, attention should be paid to the influence of a variety of factors, while refining the test steps and condition settings for the test items. The simulation should be performed in accordance with the functional relationship provided by the manufacturer when analyzing the STP.

Objective:To provide a retrospective analysis of the levels of occupational external exposure of radiation workers in Hubei province from 2009 to 2018 in a way to prevent and control its risks.Methods:The external individual doses were surveyed for 50 070 radiation workers between 2009 and 2018 by the effort of the Hubei Provincial Center for Disease Control and Prevention. Under the relevant national standards, the external radiation doses to radiation workers were conducted by using TLDs.Results:The average annual collective effective dose to radiation workers in a 10 years period was 1.93 man·Sv, the median of average annual effective dose of 0.14 mSv ( P25- P75: 0.06-0.30 mSv), and the average annual effective dose of 0.40 mSv. The annual effective doses received by 46 562 workers were less than 1 mSv, accounting for 92.99% of the total monitored workers. The annual effective dose varied dependent on occupational categories, showing a year-by-year decline trend and staying at a low level after 2012. The relative high radiation doses were seen in nuclear medicine and interventional radiology in medical applications, non-destructive testing and well logging in industrial applications, and other types of radiation applications. Conclusions:The average annual effective dose decreased year in a by year manner and kept at a low level. This indicated that the radiological protection measures taken during the 10 years ensure the health of workers. The continuous monitoring result suggest that much more attention should be paid to such categories workers as nuclear medicine, interventional radiology, non-destructive testing, well logging and others through improving radiation protection measures.

Objective To assess the medical radiation exposure frequency and find out the main factors related to the collective dose derived from X-ray diagnosis procedures. Methods A survey of 3 178 hospitals was conducted to collect the basic information such as types of medical radiation, allocation of radiological diagnosis and treatment devices, the frequency of radiologic examinations, etc. By using a stratified sampling method，36 hospital were selected and more specific details, including 26 types of diagnostic radiologic examinations, were collected to estimate the collective dose to the population in Hubei, combining with the previous literature. Results A total number of 6 843 radiological diagnosis and treatment devices were covered and 33 771 855 medical radiologic procedures were counted in this survey. The result showed a annual frequency of 569.79 examinations per 1 000 population for all types of procedures. A large variation was revealed among different areas and the highest area was with a 4-fold frequency of the lowest area. Although tertiary hospitals accounted for 4.40% of the total hospitals, 48.42% procedures were carried out in them. The collective effective dose from X-ray diagnosis in Hubei was 65 399.55man·Sv, and the average annual effective dose was 1.10mSv, while contribution from CT scans accounted for 86.90% of the dose. Conclusion The frequency of medical radiologic procedures presented a consistent increase in Hubei province, with a uneven development among hospitals from urban and rural areas, or from different regions, or from different levels. Among all types of X-ray examinations, CT scan frequency had the fastest growth rate and accounted for the major annual collective effective dose. In order to reduce the health risk from medical radiologic exposure, CT scan need to be applied more properly and the radiation dose per single CT scan need to be limited to a reasonable level.

CT is an important imaging tool for the diagnosis of novel coronavirus pneumonia (COVID-19), therefore, it′s necessary to strictly control the disinfection of CT workplace and equipment and biosafety to avoid the place from becoming a potential infection source and to reduce the risk of infection of patients and radiological staff. It is also necessary to reduce the CT scan dose to minimize the radiation hazards on patients under the premise of ensuring the CT image quality and diagnostic efficiency. Based on the survey that novel coronavirus residues after disinfection at some CT workplace in domestic and overseas and the application of low-dose CT scan in diagnosis of COVID-19, as well as the current situation of radiological protection management in emergency hospital, this paper summarizes and proposes suggestions on infection control and radiological protection for CT workplace to strengthen the defense line of COVID-19 prevention and control.

Objective: To study a method to measure the doses to planned target volume (PTV) and organ at risk (OAR) and 2D dose distribution in IMRT by using TLD and radiochromic film for a verification purpose. Methods: Totally 7 different types of medical linear accelerators were selected from seven hospitals in Hubei province. A polystyrene phantom provided by IAEA was CT scanned and then the scanned images were returned to the Treatment Planning System (TPS) for determining the prescribed doses to PTS and OAR and the corresponding MU. After the phantom was irradiated with 6 MV X-ray, the TLDs and films were transmitted to the secondary standard dosimetry laboratory of China CDC for measurement and estimation. Results: The IAEA required the relative deviations between TLD-measured and TPS-planned doses to OAR and PTV be within ±7.0%. For PTV, the measured-to-planned deviation values for 7 accelerator were within -5.4% to 6.5%, all consistent with the IAEA requirements. For OAR, the values for 5 accelerators were within -2.2% to 6.7%, not consistent the requirements, whereas the values for the other 2 were -8.6% and 8.2% respectively, beyond the required values. The IAEA required that the 2D dose distribution 3 mm/3% pass rate be higher than 90%. The measured values for 7 accelerators were in the range of 90.3%-98.9%, all consistent with the requirements. Conclusions It is feasible scientifically and easy to operate in practice for using TLD and film to carry out dose verification in IMRT. It would be advisable to apply this method to quality verification in IMRT in medical institutions to the extent possible.