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Background Individual monitoring of occupational external exposure is an essential part of the occupational health management of radiation workers, and is an important basis for the evaluation of individual absorbed dose and the diagnosis of occupational radiation diseases. Continuous participation of monitoring service providers in intercomparison is a fundamental quality assurance for routine monitoring, which can identify problems and improve them in time. Objective Taking the Laboratory of Radiation Protection in Shanghai Institute of Preventive Medicine as an example, to evaluate the performance of an individual occupational external dose monitoring system in the laboratory, identify influencing factors of the monitoring results, and provide a basis for improving the quality of daily monitoring by analyzing the process and results of a national intercomparison of individual dose monitoring. Methods According to the Testing criteria of personnel dosimetry performance for external exposure (GBZ 207-2016), and the relevant requirements of Class II (photon) inspection, a total of 20 groups of blind sample dosimeters were measured for four consecutive years from 2018 to 2021. The radiation energy source of each group was identified, and related personal dose equivalent Hp(10), the uncertainty of measurement results, and the deviation between the reported value and the reference value were calculated. The national intercomparison process and results of individual dose monitoring were also analyzed. Results The energy sources of the blind samples in the tested laboratory for four years were N100 or Cs-137. The reported dose values of the blind samples were 0.57-4.61 mSv, the combined uncertainties were 0.043-0.365 mSv, the expanded uncertainties (k=2) were 0.09-0.73 mSv, and the relative expanded uncertainties (k=2) were 13.8%-16.4%. The single-group performance ∣Pi∣ of 20 sets of blind samples in the four years was ≤0.10, the yearly comprehensive performance of 5 sets of blind samples was ≤0.10, and the yearly Q score of the test report was >15 points. The laboratory achieved excellent results in the national intercomparison of individual dose monitoring in four consecutive years, except the Q value not reaching full score. Conclusion The laboratory exhibits standardized data processing of individual dose monitoring, generates accurate and reliable results, and meets the requirements of relevant national standards; but it should continue to participate in the national intercomparison of individual dose monitoring, strengthen the angular response research of energy identified dosimeter, improve the monitoring ability of low-dose X-rays, analyze the key points of reducing the uncertainty of measurement results, and continuously improve the monitoring ability.
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ObjectiveTo determine the individual dose level and changing trend in the occupational external exposure of radiation workers in Shanghai， and provide scientific evidence for health risk assessment for radiation workers. MethodsIn the Occupational Health Management System for Radiation Workers of the National Health Commission-External Exposure Personal Monitoring and Management Subsystem， we retrieved the monitoring data of 38 077 external exposure individual dose of all medical radiation workers in Shanghai from 2015 to 2019. Using clustered sampling method， a total of 11 370 radiation workers in medical institutions （including tertiary， secondary， and primary hospitals） were selected in the study. Statistical analyses were conducted using SPSS 22.0. ResultsThe collective annual effective dose of 11 370 radiation workers was determined to be 4.340 person Sv， including 2.270 man·mSv in diagnostic radiology， 1.112 man·mSv in interventional radiology， and <0.5 man·mSv in other categories. The average annual effective dose was 0.382 mSv， which was 0.482 mSv in nuclear medicine， 0.431 mSv in radiotherapy， and <0.5 mSv in other categories. Moreover， the average annual effective dose of 6 workers （0.05%） was higher than 5 mSv， whereas that of 10 453 workers （92%） were less than 1 mSv； in addition， the annual dose of 911 workers （8.0%） was between 1‒5 mSv. All workers had average annual effctive dose lower than 20 mSv. The annual effective dose differed significantly by years （F=161.1， P<0.01）， by occupational groups （F=13.5， P<0.01）， and by hospital levels （F=264.5， P<0.01）. ConclusionThe average annual effective dose of radiation workers in medical institutions in Shanghai is lower than the national standard limit， suggesting proper and adequate radiation protection system and measures in medical institutions.
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@#<b>Objective</b> To investigate dose parameters in computed tomography (CT) scanning of common body parts inall public medical institutions in Shanghai, China, and analyze the dose distribution of CT scanning among adult subjects in Shanghai, and to provide a basis for establishing the diagnostic reference levels of CT scanning in Shanghai. <b>Methods</b> We selected at least one medical institution with CT services each from all 16 districts of Shanghai. In each medical institution, a piece of CT equipment with qualified annual inspection was sampled to investigate the doses to subjects in head, chest, abdomen, and lumbar spine scanning. We collected the basic information of the subjects, CT scanning parameters, volumetric CT dose index (CTDI<sub>vol</sub>), and dose length product (DLP). <b>Results</b> The scanning data of 1475 subjects were obtained. The 75th percentiles of the CTDI<sub>vol</sub> of the head, chest, abdomen, and lumbar spine were 57 mGy, 11 mGy, 16 mGy, and 23 mGy, respectively. The 75th percentiles of the DLP were 862 mGy·cm, 361 mGy·cm, 593 mGy·cm, and 550 mGy·cm, respectively. <b>Conclusion</b> CTDI<sub>vol</sub> and DLP differed significantly at different body parts, and also differed greatly at the same body parts. The DLP of men was slightly higher than that of women.
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Objective:To investigate the characteristics of diagnostic radiology and the situation of repeated examinations at medical institutions of Jinshan district, and put forward strategies and suggestions for the correct guidance on and reasonable applications of various medical exposures.Methods:The cases data on radiological examinations at medical institutions in Jinshan district, obtained in 2017 from Shanghai Municipal Health Commission Information Center Platform, was used to describe the characteristics of population distribution of patients, examination types, examination areas, diagnosed diseases, number of repeated examinations and the result of radiological examinations.Results:The main types of radiological examinations in Jinshan district were the CT scans and the conventional X-ray diagnosis, accounted respectively for 53.2% and 44.7% of the total radiological examinations. The radiological examinations were mainly performed on household registration (77.3%). The number of radiological examinations on males was close to on females, with examination frequency of 49.4% for males and 50.1% for females. The greatest frequency of radiological examinations was found in the age group older than 41 years, accounting for 77.1% of CT scans and 65.2% of the conventional X-ray diagnosis. The main examination sites of the CT scans at Jinshan medical institutions were chest (32.8%), abdomen (19.4%), brain (16.1%) and spine (11.4%), and for the conventional X-ray diagnosis were chest (43.2%) and limbs (39.6%). The main departments applying for radiological examinations are surgery (39.7%) and medicine (27.1%). The numbers of radiological examinations are, respectively, diseases of the respiratory system (19.8%), the injury, poisoning and some other consequences of external causes (15.8%), and the diseases of musculoskeletal system and connective tissue (15.8%). The positive rate of the conventional X-ray diagnosis was 53.1%, and the positive rate of CT scans was 73.5%. The conventional X-ray diagnosis and CT scans contributed higher specific rates of repeated examinations, accounting for 9.3% and 7.9% of the total of such type examination, respectively.Conclusions:CT scans in Jinshan district accounted for more than half of the total frequency of radiological examinations, therefore, interventions should be imposed on certain types of phycians and patients types.
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Objective:To construct back propagation (BP) neural network model to predict the dose required for 131I therapy for hyperthyroidism and to calculate the personalized dose plan for patients. Methods:A complete set of data of patients treated for hyperthyroidism radioaiodine was collected from the nuclear medicine departments of several medical colleges in Shanghai, including history, examination result, treatment course, etc. As a result, a prediction model was established. The predicated result for BP neural network, radial basis function (RBF) neural network and Support Vector Machine (SVM) were compared by means of small sample data. The optimal model was selected to predict administrated dose and to finally test the accuracy of the model.Results:The average errors in BP neural network, RBF neural network and SVM model based on small samples were 5.53%, 7.09% and 9.64%, respectively. After comparison, BP neural network was selected to build the prediction model. 30 cases of data were selected by random sampling to verify the BP neural network. The mean error, mean square error, minimum error and maximum error of the prediction result were 7.22%, 0.053, 0.57% and 13.78%, respectively.Conclusions:In this study, a neural network prediction method was proposed to provide a more accurate dose for patients in need of radioiodine therap for hyperthyroidism, and to reduce the possibility of radiation damage or the unsatisfactory therapeutic effect caused by insufficient dose. It has clinical practical significance in providing the reference for clinicians to evaluate the administrated dose.
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Objective@#To study the the application characteristics of paediatric CT examination by investigating four main children′s hospital of Shanghai.@*Methods@#All the CT scan cases of paediatric patients in this work were obtained from the radiology information system (RIS) database in four hospitals between 2011 and 2014. The distribution of using CT scans was analysed according to the age, gender, anatomical regions and the duplicated cases of the patient, then estimated the paediatric CT scan rates of four hospitals in Shanghai.@*Results@#Retrospective review of RIS showed 249 350 CT examinations from 175 672 young patients were performed between 2011 and 2014 in the surveyed hospitals. More males (62%) were scanned than females (38%). The majority of children receiving the examinations were 1 to 5 years old, which amounted to 40.3% in all. Cardiac CT accounted for 14.5% among all children of ≤1 year old CTs and accounted for 63.0% among all cardiac CT scans. There were 33 634 (19.1%) individuals who had received 2 or more CT scans during the four years. The estimated paediatric CT scan frequencies of four hospitals in Shanghai from 2011 to 2014 were 37.9 examinations per 1 000 population in 2011, 43.3 examinations per 1 000 population in 2012, 43.3 examinations per 1 000 population in 2013 and 39.0 examinations per 1 000 population in 2014.@*Conclusions@#The CT scan frequencies of four hospitals in children and young adults was almost keeping stable in Shanghai.
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Objective@#To build a comprehensive information system of radiological health in Shanghai and provide basic data for prevention and control of radiation hazards factors.@*Methods@#A management information platform of radiological health suitable for Shanghai was constructed by sorting out the historical archives and records, combining with content of current work, and using the information platform in China for reference. All Institutions are responsible for the collection and input of the data generated in the work, and the system judges the nature of the data according to the rules, and then completes the interactive analysis of the data with the municipal platform according to the standards, which forms the three-level platform management mode of the city, districts and medical institutions.@*Results@#Data module platform covering health records, environmental monitoring, business warning and statistical reports was built in one year since its preliminary inception in 2014. In the beginning there were only 468 usersof institutions, and by the end of 2018, about 1 241 users were active. Nearly 300 000 pieces of data were collected.@*Conclusions@#The construction of comprehensive management information platform of radiological health in Shanghai promotes the standardization and effectiveness of radiological health information management, provides a monitoring model for sustainable long-term development, and provides basic data for further policy management or decision-making.
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Objective To study the the application characteristics of paediatric CT examination by investigating four main children′s hospital of Shanghai. Methods All the CT scan cases of paediatric patients in this work were obtained from the radiology information system (RIS) database in four hospitals between 2011 and 2014. The distribution of using CT scans was analysed according to the age, gender, anatomical regions and the duplicated cases of the patient, then estimated the paediatric CT scan rates of four hospitals in Shanghai. Results Retrospective review of RIS showed 249350 CT examinations from 175672 young patients were performed between 2011 and 2014 in the surveyed hospitals. More males (62％) were scanned than females (38％) . The majority of children receiving the examinations were 1 to 5 years old, which amounted to 40. 3％ in all. Cardiac CT accounted for 14. 5％ among all children of≤1 year old CTs and accounted for 63. 0％ among all cardiac CT scans. There were 33634 (19. 1％) individuals who had received 2 or more CT scans during the four years. The estimated paediatric CT scan frequencies of four hospitals in Shanghai from 2011 to 2014 were 37. 9 examinations per 1000 population in 2011, 43. 3 examinations per 1000 population in 2012, 43. 3 examinations per 1000 population in 2013 and 39. 0 examinations per 1000 population in 2014. Conclusions The CT scan frequencies of four hospitals in children and young adults was almost keeping stable in Shanghai.
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Objective To build a comprehensive information system of radiological health in Shanghai and provide basic data for prevention and control of radiation hazards factors. Methods A management information platform of radiological health suitable for Shanghai was constructed by sorting out the historical archives and records, combining with content of current work, and using the information platform in China for reference. All Institutions are responsible for the collection and input of the data generated in the work, and the system judges the nature of the data according to the rules, and then completes the interactive analysis of the data with the municipal platform according to the standards, which forms the three-level platform management mode of the city, districts and medical institutions. Results Data module platform covering health records, environmental monitoring, business warning and statistical reports was built in one year since its preliminary inception in 2014. In the beginning there were only 468 usersof institutions, and by the end of 2018, about 1241 users were active. Nearly 300000 pieces of data were collected. Conclusions The construction of comprehensive management information platform of radiological health in Shanghai promotes the standardization and effectiveness of radiological health information management, provides a monitoring model for sustainable long-term development, and provides basic data for further policy management or decision-making.
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Objective To explore the distribution and application of diagnostic X-ray procedures in Shanghai through investigating the 49 sample medical institutions,to provide the theoretical basis of protective strategies for medical exposure.Methods According to the grade of medical institutions,stratified random samplings were used to select 49 medical institutions.The basic information of the surveyed medical institutions and person-times of various types of X-ray diagnostic procedures were gathered by radiology information system and manual recording.Results In the sampled medical institutions,393 sets of X-ray equipment were engaged in X-ray diagnostic radiology,and the total number of X-ray diagnostic imaging was 4 442 662.The gender ratio of male and female was 1 ∶0.99.The total frequency of diagnostic X-ray procedures was 1 228 examinations per thousand population,including 304 examinations per thousand population of CT scan,105 examinations per thousand population of dental radiography.Conclusions The frequency of diagnostic X-ray procedures in 2016 increased compared with the data surveyed during the period of the " 11th Five-year Plan",in which the frequency of CT procedures increased significantly.
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Objective To study the effect on the environmental radioactivity level and the health of the residents in Shanghai when Qinshan Nuclear Power Station(QNPS) has been in normal operational condition for 17 years. Methods The field monitoring and the sampling analytical method were used for monitoring the radioactivity level in outdoor environment, drinking water, food and soil. Results The outdoor natural radiation level and the radioactivity level in the sample of the environmental media were on the normal background level. There was no distinct change in the environmental radiation level of Jinshan Area when QNPS was in normal operational condition. The radioactivity level in the environmental media was far lower than the limit values specified by the national standard GB. The effective dose of the outdoor natural external exposure for the residents is about 0.102 mSv/a and the effective dose of the internal exposure from the artificial radionuclides 90Sr and 137Cs in food for the residents is about 0.488 μSv/a. Conclusions There is no effect of the radioactive contamination on the environmental radioactivity level and the health of the residents in Shanghai when QNPS has been in normal operational condition for 17 years.