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Objective To calculate the absorbed doses and conversion coefficients of various organs in humans after oral administration of urea-14C, and to provide a convenient method for evaluating the internal radiation dose caused by ingestion of urea-14C in Chinese population. Methods The Chinese reference human voxel model was imported into the FLUKA software to simulate the absorbed doses to organs under internal exposure to 14C, and to obtain the dose conversion coefficients for oral administration of urea-14C. Results The absorbed dose conversion coefficients for the stomach, colon, bladder, heart, and muscles were 0.029, 0.029, 0.32 (0.24), 0.028, and 0.029 mGy/MBq in negative cases, and 0.079, 0.078, 0.18 (0.15), 0.076, and 0.080 mGy/MBq in positive cases. The committed effective dose coefficients were 0.041 (0.037) mSv/MBq in negative cases and 0.082 (0.081) mSv/MBq in positive cases. Conclusion The dose conversion coefficients obtained in this study can provide important parameters for evaluating the absorbed dose to Chinese population after oral administration of urea-14C.
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The rational use of medical insurance fund(MIF) plays an important role in promoting the high-quality development of public hospitals, and the supervision of MIF is in a trend of under the rule of law, normalization, professionalization and standardization, and unannounced inspection will become the norm. The authors systematically analyzed three main trends of MIF unannounced inspections, namely, gradually increasing intensity, constantly innovating methods, and increasingly serious consequences. The problems exposed in unannounced inspections were sorted out from five dimensions: form of results, severity, scope of attribution, subjective intention, and regulatory screening ideas. The enlightenment of MIF unannounced inspections to hospital management was explored from four aspects: compliance awareness, organizational system, fine management, and daily supervision. It was proposed that public hospitals should transform their roles and positions, improve the working mechanism of departmental collaboration, and achieve fine management in policy understanding, system formulation, process design, information support, data governance, regulatory implementation, personnel training, and performance matching. At the same time, internal simulated unannounced inspections in hospitals should be regarded as a routine work.
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Objective To analyze the impact of different maze structures of medical electron linear accelerator on the radiation level at the entrance of the treatment room. Methods The Monte Carlo simulation method was used to compare the radiation field distribution in two accelerator rooms with different maze widths and to conduct a detailed analysis of the radiation levels. Results The radiation level at the entrance of the accelerator room with a wide maze was significantly higher than that at the entrance of a compact maze. The neutron radiation level at the entrance of the narrow maze model decreased by 38.6% compared to the wide maze model, and the level of X-ray radiation also showed a declining trend. Conclusion When designing medical electron linear accelerators, a compact maze structure should be adopted to reduce the setting of unnecessary space, thereby lowering the radiation level at the entrance of the treatment room and enhancing the effectiveness of radiation protection.
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Objective To investigate the current situation of occupational stress among radiation workers in nuclear power plants in China, to explore the factors influencing occupational stress, and to provide a reference for improving occupational stress. Methods A convenient sampling method was adopted to investigate the occupational stress of 100 radiation workers in two nuclear power plants in Fujian and Liaoning, using the general situation questionnaire, effort-reward imbalance questionnaire, and the radiation protection knowledge questionnaire. Independent samples t-test, one-way analysis of variance, chi-square test, and binary logistic regression analysis were used to examine the current situation of occupational stress and the influencing factors. Results The average value of effort-reward imbalance was 0.99 ± 0.15 and 47 (47%) radiation workers had occupational stress. There were significant differences in the detection rate of occupational stress among radiation workers with different ages, years of radiation work, monthly incomes, sleep durations (day), and exercise habits (P < 0.05). Logistic regression analysis showed that monthly income, sleep duration (day), and exercise habits were the influencing factors for occupational stress. Conclusion The occupational stress of radiation workers in nuclear power plants is a serious issue influenced by many factors. Attention should be given to this issue, and targeted interventions should be implemented to improve the social and working environment of this occupational group and reduce the level of occupational stress.
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In recent years, occupational stress has become a focus of public attention in public health in China and abroad. Radiation workers are exposed to ionizing radiation in their daily work, which further exacerbates their levels of occupational stress. This not only affects their physical and mental health, but also increases the potential for radiation incidents or accidents. Based on the literature on occupational stress among radiation workers in China throughout the years, this article provides a summary, conclusion, and systematical analysis of the research status of occupational stress among radiation workers, with a detailed sorting of the data. It explores key research issues and directions and provides reference for future work.
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Objective:To evaluate the impact of sarcopenia on survival and treatment-related toxicity in postoperative recurrent esophageal squamous cell carcinoma (ESCC) patients treated with chemoradiotherapy.Methods:Clinical data of 147 patients with postoperative locoregional recurrent ESCC receiving chemoradiotherapy in Huai'an First People's Hospital from 2016 to 2017 were retrospectively analyzed. Pectoralis muscle area (PMA) was determined using routine pre-radiotherapy CT simulation scan above the aortic arch level. Sarcopenia was defined as a cut-off value of pectoralis muscle index (PMI) (PMA/height 2) <11.55 cm 2/m 2 for males and <8.69 cm 2/m 2 for females. The incidence of toxicity, 1- and 3-year overall survival (OS) rates were statistically compared between patients with and without sarcopenia. Results:Sarcopenia was detected in 49 of 147 (33.3%) patients. The incidence of grade 3-4 toxicities in sarcopenic patients was significantly higher compared to that in their counterparts without sarcopenia (40.8% vs. 18.4%, P=0.005). In addition, patients with sarcopenia had significantly worse 1-year (61.2% vs. 82.7%) and 3-year OS rates (10.2% vs. 28.6%) than those without sarcopenia (both , P<0.001). Multivariate analysis showed that sarcopenia was an independent prognostic factor for poor OS ( P<0.001). Conclusion:PMI based on CT simulation scan has prognostic value in postoperative locoregional recurrent ESCC patients treated with chemoradiotherapy, which probably serves as a novel diagnostic tool for sarcopenia.
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Digital and intelligent technology is an important driving force to promote the transformation and innovation of medical service mode and improve service quality. In February 2020, Peking Union Medical College Hospital established an intelligent outpatient pre-admission medical history collection system in order to improve the intelligent level of clinical application business system and the medical experience of outpatients.The system consisted of artificial intelligence capability layer, application service layer, capability resource layer and user application layer and hardware technology architecture. By docking with the hospital information system and using mobile terminal App, patients could submit pre-admission medical history information by themselves, and generate structured patient history for the visiting doctors to call. By November 2021, the pre-admission medical history collection system had covered 80% of the departments of the hospital, serving 1.68 million people in total, and the patient filling rate had reached 60%. The duration of patient′s medical history collection and the duration of doctor′s outpatient electronic medical record writing had been continuously shortened, greatly improving the efficiency of outpatient medical services.
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Objective:To develop and test a software which can get and count the medical exposure frequency automatically.Methods:This study was based on the investigation of the frequency of radiodiagnostic medical procedures in China over the past by reference to the experience gained from the Electronic Medical Record Sharing and Reporting System in Beijing. The core elements for collecting the number of medical procedures and radiodiagnostic categories were determined. The collection process was then designed and the collection program software was written in a way for deployment on the front-end computer system of a general hospital for trial.Results:The field table to collect the number of medical procedures and the corresponding data structure were generated, and the data collection and statistics of the above fields were realized based on the survey data of DR and CT diagnostic examination frequency in a hospital in 2021. It took 15 s on average, and the statistical result are consistent with the manual statistical result using RIS source table.Conclusions:The software can realize the automatic acquisition and reporting of the number of radiodiagnostic medical procedures in hospital on a regular basis, which is worth promoting.
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Objective:To conduct radiation detection and dose assessment in selective internal radiotherapy with 90Y resin microspheres for the purpose of providing a reference for radiological protection. Methods:The dose rates from radiotherapy with 90Y resin microspheres were detected in the process of each operation at different distances from the body surface of patients the levels of dose to the persons concerned were compared with the relevant national regulations and standards. Results:The estimated dose rates were 1.12-454 μSv/h during 90Y resin microspheres dispensing and 2.06-58.2 μSv/h during surgical procedure. The dose rates at 0.5 h after surgery were 22.7-64.1 μSv/h at 5 cm and 0.82-2.55 μSv/h at 1 m from three patient′s body surface. Assuming treating 200 patients a year, the annual individual effective dose to the radiation workers was 0.12-1.03 mSv/year. The annual individual effective dose to the public, comforters and carers of patients was 0.02-0.24 mSv/year after release of a patient. Conclusions:During the treatment, nursing and release of patients, the radiation doses to workers, carers and the public are lower than the individual dose limit given in the GB18871-2002 basic standards for protection against ionizing radiation and for the safety of radiation sources and the management target value set by of the relevant medical institutions.
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BACKGROUND@#Lung cancer incidence in Macao increases gradually, smoking is one of the important high risk factors. The purpose of this study is to observe the detection rate of lung cancer and nodules in long-term smoking Macao individuals.@*METHODS@#We recruited eligible Macao residents by publicity, all subjects were arranged to receive low-dose computed tomography screening. Image features of lung nodules were analyzed by radiologist. For suspicious lung cancer, multiple disciplinary team (MDT) was arranged.@*RESULTS@#A total of 291 were adopted, 10 lung cancers were detected, the detection rate of lung cancer was 3.44% (95%CI: 2.78%-4.01%), all were males. There were 5 adenocarcinoma patients, each 2 squamous-cell carcinoma and small cell lung carcinoma patients; 1 adenosquamous cancer patient. Among 10 lung cancers, 40% had stage 1 disease. The detection rate of lung nodules was 72.9% (95%CI: 67.8%-78.0%); The number of suspicious lung nodules were 44, and the detection rate was 15.1% (95%CI: 11.0%-19.2%). There was no significant differences in the lung cancer detection rate between the single and multiple lung nodule groups (P>0.05). There were 168 subjects in the <6 mm solid lung nodule (SN) and <5 mm no-solid lung nodule (NSN) group and no lung cancer was found, 44 subjects in the ≥6 mm SN and ≥5 mm NSN group. All 9 lung cancer patients were detected in this group. The detection rate of lung cancer was higher than that of the <6 mm SN and <5 mm NSN group (P<0.05).@*CONCLUSIONS@#There are high detection rate of lung cancer and lung nodule in the long-term smoking individuals. The lung cancer rate increases when the lung nodule size is larger than 6 mm in SN and 5 mm in NSN. Adenocarcinoma is the major type in the smokers' lung cancers. We suggest long-term smokers should join in the future lung cancer screening trial in Macao. Female lung cancer screening should be established different standard.
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Objective:To verify and discuss the consistency and applicability of the semi empirical formula and Monte Carlo simulation method in the radiation shielding calculation for high energy synchrotron radiation source.Methods:The semi empirical formula and Monte Carlo simulation were used to calculate the ambient dose equivalent outside of the shielding.Results:The ratio of Jenkins semi empirical formula result to Monte Carlo simulation result was 111%-153%. The ratio of Sakano semi empirical formula result to Monte Carlo simulation result was 201%.Conclusions:For a single shielding material, the semi empirical formula can be simple and conservative to complete the shielding calculation for high-energy electron accelerator. For a variety of shielding materials, Monte Carlo simulation method should be used.
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Objective:To analyzes the current status of radiation protection in non-medical sectors, together with the vulnerable spots in the prevention and control of occupational radiation sickness in China in order to provides both technical basis for occupational health management in non-medical radiation sectors and the better protection of occupational health benefits for radiation workers.Methods:The monitoring plan for this survey was worked out on the part of the National Institute for Radiological Protection, China CDC. Survey and monitoring of the current status of radiation protection and occupational health management were, under the monitoring the plan, completed by the relevant agencies of all provincial-level regions for the key industries of non-medical sectors countrywide, involving occupational health monitoring, personal dose monitoring, radiation protection monitoring instruments equipped, and radiation protection monitoring in workplace. Based on the survey result , the deficiencies in radiation protection and occupational health monitoring in non-medical sectors were analyzed.Results:The survey of non-medical sectors was divided into general investigation and detailed monitoring, with the general investigations covering 9 075 non-medical institutions in 31 provincial-level regions across the country. Of them, a total of 4 911 institutions within 329 district-level regions received detailed investigation and radiation protection monitoring. As survey result , the X, γ ambient dose equivalent rates for the institutions using ray-generator are greater than 2.5 μSv/h, about 2.35% of the total, with a maximum of 817 μSv/h. The values for those using radioactive sources were greater than 2.5 μSv/h, about 9.57%, with a maximum of 1 700 μSv/h. The frequencies of personal dose monitoring and occupational health examination were 72.9% and 82.1%, respectively.Conclusions:There is still a gap in radiation protection between the current status and the national regulations and standards in non-medical sectors, so both regulation and management of radiation protection should be further strengthened.
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Objective:To explore the existing issues in radiation protection during the treatment of 131I by means of measuring the ambient dose equivalent rate to patients with thyroid cancer and the dose equivalent to the surface of chest of patients during hospitalization. Methods:The ambient dose equivalent rate (peer) was measured by using gamma ray detector for selected 78 patients who received 131I treatment in a hospital 10 min, 1 d, 2 d, 3 d and 5 d after administration with 131I. The measurements were made at distances of 5 cm, 0.5 m and 1 m from the body surface in front, rear, left and right directions. The photoluminescence dosimeter on the chest of the patients was used to measure the effective dose during hospitalization period (6 d). Results:The ambient dose equivalent rate on the surface of chest of patients was up to 4.81 mSv/h 10 min after administration of medicine. The dose equivalent on the surface of chest of patients before discharge ranged 2.6-64.1 μSv/h. The cumulative dose on chest surface during hospitalization was 15.9-58.8 mGy. There was a significant difference in the dose rate at 5 cm from the body surface between 3.7 GBq group and 5.55 GBq group 10 min after medication ( t=-6.11, P<0.05). There was a significant difference in the dose rate at 5 cm from the body surface between male and female groups 10 min after medication ( t=4.52, P < 0.05). There was no significant difference in other groups ( P > 0.05). Conclusions:During the 131I treatment, patients had high level of radiation around them, so it is necessary to strengthen the protection and management of patients and reduce unnecessary exposure to the public.
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Objective To realize the efficient monitoring of frequency of medical exposure and dose monitoring in Ningbo by means of informatization. Methods Data transmission process and the key elements of frequency of medical exposure and individual dose were investigated. According to standardization principles of data elements, the standardized data elements for frequency of medical exposure and individual dose were determined. On this basis, modules and functions of data receiving platform on the frequency of medical exposure and individual dose in Ningbo were designed. Results Totally 59 data elements on frequency of medical exposure and individual dose were formed. According to their functions, the data receiving platform was divided into the distribution of radiodiagnosis and radiotherapy resources, the frequency monitoring of medical exposure and dose monitoring for permanent residents, and the dose monitoring. Conclusions The establishment of frequency and dose information monitoring platform on medical exposure in Ningbo and the determination of standardized data elements will be conducive to further progress in medical exposure information monitoring in Ningbo.
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Objective@#To realize the efficient monitoring of frequency of medical exposure and dose monitoring in Ningbo by means of informatization.@*Methods@#Data transmission process and the key elements of frequency of medical exposure and individual dose were investigated. According to standardization principles of data elements, the standardized data elements for frequency of medical exposure and individual dose were determined. On this basis, modules and functions of data receiving platform on the frequency of medical exposure and individual dose in Ningbo were designed.@*Results@#Totally 59 data elements on frequency of medical exposure and individual dose were formed. According to their functions, the data receiving platform was divided into the distribution of radiodiagnosis and radiotherapy resources, the frequency monitoring of medical exposure and dose monitoring for permanent residents, and the dose monitoring.@*Conclusions@#The establishment of frequency and dose information monitoring platform on medical exposure in Ningbo and the determination of standardized data elements will be conducive to further progress in medical exposure information monitoring in Ningbo.
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Objective@#To investigate the effect of iron shield at different depths within main protection wall on the dose rate outside the protection wall.@*Methods@#By adopting the FLUKA code, a therapeutic room model was constructed with its primary protective barrier consisting of concrete and iron. In order to obtain its ambient dose equivalent rate distribution, the 250 MeV protons and 220 MeV protons impinging on water phantom were simulated separately.@*Results@#With varying depth of iron plate embedded in barrier, the ambient dose equivalent rates in the two simulated conditions differed sinificantly at 30 cm outside the protection wall. The maximum ambient dose equivalent rate(220 MeV: 3.42 μSv/h, 250 MeV: 6.39 μSv/h) was more than 2 times higher than the minimum ambient dose equivalent rate(220 MeV: 1.75 μSv/h, 250 MeV: 3.32 μSv/h).@*Conclusions@#In the design of therapeutic proton accelerator, it is essential to evaluate carefully the location where the iron shield is in main protection wall.
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Objective To investigate the effect of iron shield at different depths within main protection wall on the dose rate outside the protection wall. Methods By adopting the FLUKA code, a therapeutic room model was constructed with its primary protective barrier consisting of concrete and iron. In order to obtain its ambient dose equivalent rate distribution, the 250 MeV protons and 220 MeV protons impinging on water phantom were simulated separately. Results With varying depth of iron plate embedded in barrier, the ambient dose equivalent rates in the two simulated conditions differed sinificantly at 30 cm outside the protection wall. The maximum ambient dose equivalent rate(220 MeV:3.42 μSv/h, 250 MeV:6. 39 μSv/h) was more than 2 times higher than the minimum ambient dose equivalent rate ( 220 MeV:1. 75 μSv/h, 250 MeV: 3. 32 μSv/h ) . Conclusions In the design of therapeutic proton accelerator, it is essential to evaluate carefully the location where the iron shield is in main protection wall.
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To ascertain the background and frequency of diagnostic medical X-ray procedures in China and provide the basis for regulatory oversight of such applications,a total of 557 medical institutions in 25 provinces or municipalities were surveyed by means of the optimally designed questionnaires and through stratified quota sampling.The numbers of procedures were calculated in terms of the type of procedures and the sex and age of examined patients.As a result,the frequencies of diagnostic X-ray procedures for 2016 in the country were derived using multiple linear regression analysis.The frequency of X-ray diagnosis in 10 provinces of China in 2016 was estimated to be 379-1 228 examinations per 1 000 population.Diagnostic X-ray applications have shown a rapid expansion in 2016 as compared with the period of "9th Five-Year Plan".It is very important to strengthen the regulation of medical diagnostic X-ray applications.
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Objective To simulate and analyze the CT examination doses to typical patients based on Chinese reference human phantom, and to develop an online software for assessing the organ absorbed dose and effective dose to the examinees undergoing CT examination in order to provide a tool for rapid assessment of radiation dose from CT examination. Methods Based on the Monte Carlo simulation, a GE LightSpeed 16 CT scanner was modeled. The organ doses to Chinese adult male, female and 1 year-old child male from single axial scan were calculated based on the Chinese reference phantoms and an organ dose database was established. A web-based CT dose assessment software was developed to read the data from the organ dose database according to the CT scanning parameters entered by the user and to calculate the organ absorbed dose and effective dose rapidly. Results A new CT dose assessment software was developed, which can be used to assess organ doses to Chinese adult male, female and 1-year-old male for different CT scanner, voltage, current, collimator width and other CT parameters. The organ doses calculated in this work were compared with simulation data in two relevant studies. Dose differences for the organs completely included in the scan range were small, with relative differences less than 15％ and 25％, respectively. Conclusions The CT dose assessment software provides a powerful tool for the simple and rapid assessment of radiation dose to the examinees undergoing CT examinations.
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Objective To validate and discuss the time response correction formula for four types of dosimeters (6150AD6 + 6150AD-b,FH40G + FHZ672E-10,451P ionization chamber and AT1123).Methods The ambient dose equivalent rates shown by survey meters were recorded separately when X-ray emission time was 500,200,100 and 50 ms.The corrected values were obtained by the formula of circuit having a capacitance C and asistance R in series.Results Therewas no correlation between the value measured by AT1123 dosimeter and the time of irradiation.The values by other three kinds of dosimeters obviously varied with the time of irradiation.Conclusions It is not required to make the time response correction for the measured value of ATl123 dosemeter,whereas the values measured by the other three dosimeters could be corrected by the time response correction formula.