Objective To know well the exemption criteria and exemption levels of radioactivity from regulatory control.Methods It was done in accordance of the standards and other information on hand about exemptions of radioactivity.Results Some proposals for using exemption criteria and exemption standards are put forword.Conclusion It is imperative to understand and use precisely these proposals.

Objective To comprehensively evaluate the radiation protection of ¹⁷⁷Lu-Dotatate therapy, and to provide a reference for standardizing and restraining patient behavior and activities after discharge and establishing relevant standards. Methods The radiation protection of ¹⁷⁷Lu-Dotatate therapy started with the infusion of radiopharmaceuticals. The time points of each event in daily activities during and after therapy were listed in a chronological order, as well asthe persons with possible radiation exposure and their contact distance and contact duration in each event. The in vivo pharmacokinetic data in the instructions of ¹⁷⁷Lu-Dotatate were used to estimate ¹⁷⁷Lu activity in the patient’s body at each time point, and the formula for radiation dose in GBZ 120—2020 was used to estimate the radiation dose of the patient on the persons around him/her. Results ¹⁷⁷Lu-Dotatate was administered to the patient at a dose of 7400 MBq when the patient attended the outpatient service or was hospitalized for treatment. The cumulative radiation dose was calculated for the medical staff, the public, colleagues, caregivers, adult family members, and the family members of children aged 3~10 years, and the measures for standardizing and restraining the patient’s behaviors were given when the dose constraint value for related persons in national standard was met. The conditions for realizing the requirement in national standard that pregnant women and family members aged < 3 years should avoid contact was also proposed in this article. Conclusion From the perspective of radiation protection, under the premise of standardizing and restraining the behavior of patients treated with¹⁷⁷Lu-Dotatate after discharge, both ambulatory treatment and hospitalization are safe and feasible; if the activities of patients are no restrained after discharge, the radiation dose for family members, the public, and colleagues might exceed the dose limits or constraint values in relevant national standards.

Uranium is an important radioactive actinide in nature and an important nuclear material in nuclear industry. After uranium is accidentally released into the environment, it enters the body through the respiratory tract, the digestive tract, and other ways, then enters the circulation system through blood, and is finally mainly deposited in the kidney and bone, causing a certain degree of toxicity. Therefore, efficient low-toxicity chelators are an important way to reduce radionuclide pollution, radiation damage, and chemical toxicity. This article reviews uranium deposition and harm, the detoxification mechanism of uranium chelators, and the research advances in uranium chelators and points out the development trend of uranium chelators.

In order to better promote the effective implementation of GBZ120—2020 Requirements for Radiation Protection in Nuclear Medicine, this paper will start by introducing the key content of the latest relevant standards and technical specifications of the International Atomic Energy Agency, and then analyze the relatively entangled issues in the domestic implementation of GBZ120—2020, so as to promote our country's strict and effective implementation of the national mandatory standard GBZ120—2020, improve the level of radiation protection of our country’s professionals, members of the public, and those involved in medical exposure.

Radiotherapy plays an important role in the treatment of malignant tumors, and how to improve the radiosensitivity of tumors is a major topic of clinical and basic research. Radiation can cause multiple forms of DNA damage, and the repair process after DNA damage will lead to the decrease of radiosensitivity of cancer cells, even radiation resistance. In this paper, the mechanism of DNA damage repair and its effect on radiosensitivity of malignant tumors are reviewed.

In this paper, the characteristics, clinical manifestations, diagnostic criteria and treatment principles of acute and chronic radiation skin injury caused by external irradiation were analyzed based on domestic and foreign literatures, newly formulated national occupational health standards and the author's clinical experience, etc., which provide basis for timely treatment and standardized diagnosis and treatment of radiation skin injury. Acute radioactive skin injury is divided into Ⅰ, Ⅱ, Ⅲ and Ⅳ degrees according to the size and clinical manifestations of the irradiated dose. The clinical course of these four degrees of acute radioactive skin injury not only showed the association between dosage and injury, but also showed the obvious phases of severe radiation injury. Early dose estimation through skin injury degree is helpful for rapid and accurate diagnosis, early prediction of lesion severity and decision of treatment strategy. Chronic radioactive skin injury is caused by long-term exposure to low-dose radiation due to occupational reasons; Another reason is prolonged formation of acute radioactive skin injury, which divided into Ⅰ, Ⅱ and Ⅲ degree. It is only classified according to the degree of skin injury and has no strict dose-effect relationship with the radiation received. The treatment of acute and chronic radioactive skin injury is different according to the degree of injury. Local conservative treatment and surgical treatment using repair methods all consider the promotion effect of systemic treatment on wound healing.

目的 为了正本清源,理清目前核技术利用单位及监管部门对豁免概念及其审查中相关问题处理的思路,依法行政。方法 本文从对豁免定义理解的讨论着手,对我国目前对豁免的管理方式进行了阐述,并针对豁免审评中一些值得关注的问题进行了分析。结果 对豁免对象、含放射源设备的豁免条件、豁免含源设备中放射源的管理、辐射水平检测以及对含有多种放射性核素物质的豁免这些存在问题较多的环节进行了梳理和分析。结论 对规范目前放射性豁免管理具有指导意义。

In order to accurately understand and apply the health standard WS 519—2019 (Specification for testing of quality control in X-ray computed tomography), the background, basis, principles, and main revisions of the standard are introduced, the scope of application and quality control requirements described in the standard are clarified, and CT quality control and test procedures are explained in detail. This standard interpretation can be used to guide institutions to work in a more standard way for the quality control and test of CT machine to better protect the safety and health of CT operators and patients.

Tritium (³H) is an isotope of hydrogen. The main sources in the environment are natural tritium and artificial tritium.Artificially produced tritium appears as a by-product or a key fuel in the development of nuclear energy, and its release rate far exceeds that of natural tritium. The public's exposure to tritium in the environment is very low. Strategically speaking, the protection of tritium should focus on occupational exposure workers. This article briefly summarizes the nature, source, hazards, protection and pollution treatment of tritium, so that the public and radiation workers can understand relevant knowledge and do personal protection.

Objective To analyze the results of ranging error detection and discuss its influencing factors, so as to control the imaging link of DR detector.Methods Referring to “the medical digital X-ray photography (DR) system quality control test specification ”(WS 521—2017), the DR ranging error detection results were processed. Meanwhile, DR equipments from the same manufacturer were selected for horizontal comparison and those from different manufacturers for vertical comparison.Results The overall qualification rate of DR ranging error was not high, with an average qualification rate of 63.6%. The qualification rate reached 100% after ranging correction.Conclusion Further refinement of detection methods and reduction of data acquisition errors can effectively improve the qualification rate of ranging errors, which is of great significance to medical X-ray image diagnosis.

目的 介绍医用电子直线加速器的相关法规和标准以及质量保证(QA)的主要内容及检测方法 ,使加速器的应用质量保证工作有章可循,从而提高放射治疗的准确性和精度。方法 从国家文件中整理出医用电子直线加速器所执行的相关标准;并从医用电子直线加速器机械等中心,多叶准直器,射线和激光灯的对中校准,X射线与电子线剂量学特性,剂量刻度,楔形板及治疗附件,电子射野影像系统以及辐射防护与安全连锁等方面分析确认QA的主要内容和检测方法。结果 得出了医用电子直线加速器应符合相关的标准以及QA主要内容及检测方法。结论 作为医用电子直线加速器的相关标准和QA主要内容及检测方法,对各级放射治疗单位医用电子直线加速器QA体系的建立具有现实指导作用。

In April 2021, the Japanese government decided to discharge nuclear wastewater from the Fukushima Daiichi nuclear power plant into the sea, which aroused widespread concern all over the world. The radioactive substances in nuclear wastewater may affect the environment through the action of ocean circulation, groundwater or carbon cycle. In addition, it may expose people to the health effects of low-dose but long-term pollution once nuclear wastewater is discharged into the sea. Based on this, this paper discusses the possible global environmental impact of nuclear wastewater from a general perspective and illustrates its possible health effects as well as potential mental health problems from an individual perspective, and puts forward some suggestions on the issue of Fukushima nuclear wastewater discharge.

Objective To explore the effect of change in occupational internal dose coefficients on estimation of the internal exposure dose of radiation workers. Methods Forty-one radionuclides were selected as the research objects, and their new and old occupational internal dose coefficients were summarized. The change in internal dose coefficients was analyzed by calculating the ratios of dose coefficients and using the frequency distribution of ratios.Results The occupational internal dose coefficients of the 41 radionuclides analyzed had all changed, with ratios ranging from 0.1 to 4.5, and the maximum difference reaching 10 times (when the ratio was equal to 0.1).Conclusion It is recommended to revise the national standards concerning occupational internal dose coefficients in time and update the occupational internal dose coefficients, so as to better monitor the occupational health of radiation workers.

Objective To provide suggestions for ensuring a rational and orderly field medical emergency rescue, and minimizing the hazards of nuclear and radiation accidents. Methods According to domestic and foreign laws, regulations and standards, combined with the experience of our research involving in nuclear medicine and radiation accident emergency preparedness and response, the study of triage for wounded persons was carried out. Results Characteristics of wounded persons in nuclear and radiation accidents were clarified, and the classification principle, labeling and Methods were initially proposed. Conclusion The triage method would play an active role in scientific classification and orderly rescue for wounded persons in nuclear and radiation accidents.

People are more often exposed to low as opposed to high doses of ionising radiation (IR). Radiation epidemiology and clinical studies have shown that low dose or low dose rate ionizing radiation are risking to induce cancer and other non-malignant diseases,such as congenital abnormalities, cardiovascular and cerebrovascular diseases, cataract, etc. Furthermore, low dose or low dose rate radiation could also give risk to benefitial effects for human being. The effects of low dose or low dose rate ionizing radiation on human health are briefly reviewed and discussed.

在世界性范围内,胸部放射诊断学在医疗照射中占大约50%的份额^[1],胸部X射线影像能给临床医生提供充分的诊断信息,在可以预计的将来,这种重要作用仍将继续下去^[2]。

目的 评价放射工作人员的健康状况,了解长期小剂量电离辐射对放射工作人员健康的影响,为放射健康监护管理工作提供科学依据。方法 按照卫生部《职业健康监护管理办法》和《放射工作人员健康标准》规定的检查项目,2010年对万州区及周边6县415名放射工作人员进行了职业健康检查。结果 临床检查异常人数249人,占受检放射工作人员总数的60.00%;实验室检查异203人,占受检放射工作人员总数的48.92%,其中放射性敏感项目异常检出率白细胞减少6.75%、红细胞减少0.24%、血红蛋白减少1.93%、血小板减少3.13%,其他项目异常检出率为肝功能11.81%、肾功能6.75%、尿常规17.35%;染色体畸变异常检出人数为7人,淋巴细胞微核异常检出人数为30人,异常率分别为1.69%和7.23%;不符合国家健康标准的人员占受检放射工作人员总数的10.36%。结论 导致万州区及周边6县放射工作人员健康检查不符合国家健康标准规定的主要原因是淋巴细胞微核率升高,其次为染色体畸变率升高、白细胞减少和血小板减少。因此,必须提高放射工作人员的防护意识,加强放射工作场所的防护和人员的健康监护管理工作。

Objective To optimize the measurement and analysis method for carbon-14 in environmental biological samples, and to provide technical support for the formulation of standard methods for carbon-14 measurement in environmental biological samples. Methods Through the optimization research on the carbon dioxide absorption method, the moisture content and carbon content of biological samples were measured with the moisture meter and the element analyzer according to the simplified personnel operation and the optimized process steps of the method, and intra- and inter-laboratory validation of the method was carried out. Results Under typical conditions, the lower limit of detection of the method reached 3 Bq/kg, and there were a relative standard deviation within laboratories of less than 17% and a relative standard deviation between laboratories of less than 14%, with a relative error of less than 19%. Most of the sample pretreatment was directly completed by the instrument and equipment, which improved the precision and accuracy of the measurement of moisture content and carbon content in samples, and reduced the influence of experiment personnel’s operation differences on the test results. Conclusion The lower limit of detection, precision, and accuracy of the optimized method meet the relevant requirements for the determination of carbon-14 in biological samples.

Objective To simulate mobile cone-beam computed tomography (CBCT) imaging based on the Geant4/GATE platform and to explore the optimization method to improve image quality. Methods Mobile CBCT imaging was simulated based on the Geant4/GATE platform of Monte Carlo algorithm to establish the models of X-ray source, flat panel detector, and phantom, and projection data of CBCT were obtained. Three image reconstruction algorithms (FDK, SART, and EM) were used for image reconstruction of the designed digital phantom with the projection data at two X-ray energy levels. Results FDK was the fastest algorithm, SART had high contrast quality, low artifacts, and high image quality; EM had minimum noise but fuzzy boundaries of inserts of different density. With the SART algorithm, the images reconstructed at 70 kV X-ray were scatters, while the images reconstructed at 140 kV X-ray had high quality. Conclusion Simulation of mobile CBCT based on the Geant4/GATE platform can reconstruct 3D images of the digital phantom, which provides a theoretical basis for further research on image quality optimization and quality control of mobile CBCT.

目的 探讨热释光个人剂量监测中本底值与MDL值的各种影响因素,合理应用本底值和MDL值。方法 按变异系数小于5%的要求选用一种型号的LiF(Mg,Cu,P)探测器,探测器放在剂量计壳内和壳外以及放置在实验室不同位置,放置周期与服务监测的周期一致,按常规测量程序,求出本底值和MDL值。结果 探测器放置在剂量计壳内与壳外以及剂量计放置在不同位置,对本底值影响明显,而MDL值差别不大。结论 实施热释光个人剂量监测时,应依托自身剂量测量系统,测量和计算本底值和MDL值;本底剂量计应将探测器置于剂量计壳内,放置在实验室距离墙、地面尽量远的地方,避免由于建筑和装饰性材料放射水平影响本底值。

Monitoring data of radionuclides in food is a valuable data source for public health risk assessment. Since 2012, the monitoring of radioactive substances in food in China has been continuously advancing. Continuous monitoring can improve early warning and control capabilities, and provide a scientific basis for food safety risk assessment under normal conditions and emergencies. This article summarizes the current radioactivity measurement standards of China in environment and food, introduces the current status of radioactive substances monitoring in food, discusses issues worthy of attention, and summarizes the challenges and prospects of food radioactive substance monitoring, looking forward to providing scientific guidance for future research.

目的 了解和分析濮阳市医用常规X射线诊断设备影像质量控制现状,为提高医用常规X射线诊断设备水平和卫生行政执法监督提供依据。方法 按照《医用常规X射线诊断设备影像质量控制检测规范》对正在运行中的32台摄影设备和21台透视设备进行状态检测。结果 12台摄影设备影像质量控制检测不合格(37.50%)、5台透视设备像质量控制检测不合格(23.81%),其余均合格。结论 为保证医用常规X射线诊断设备影像质量控制水平、提高医用常规X射线诊断设备影像质量,必须加强对医用常规X射线诊断设备的影像质量控制的状态检测和自主稳定性检测工作,及时调试和校正医用常规X射线诊断设备的各项质量控制性能指标。

In the process of natural uranium purification and conversion, low-level uranium-containing radioactive wastes will be produced. On the basis of introducing the characteristics of wastes from natural uranium purification and conversion and their treatment, we review the main strategies and good practices of minimization of wastes from natural uranium purification and conversion, analyze the main problems in minimization of wastes from natural uranium purification and conversion in China, and propose corresponding improvement measures, which provides a reference for the implementation and management of minimization of wastes from natural uranium purification and conversion.

Objective To provide scientific data for the study of tumor prevalence among medical X-ray workers. Methods In a cohort study, radiation exposure and tumor occurrence were collected from medical X-ray workers and normal persons (control) in Chongqing, China. SPSS 24 software was used to calculate the incidence density of tumor in the follow-up cohort, as well as the relative risk (RR) and 95% confidence interval of various malignant tumors. Results A total of 934 subjects were followed up. By the end of the investigation, 109 cases of malignant tumor were recorded. Compared with the control group, the RRs of liver cancer and colorectal cancer were both 3.4. Dose-specific RR was calculated for the worker groups. Compared with the two groups with < 80 mGy and 80～200 mGy cumulative doses, the group with > 200 mGy cumulative dose showed 2.05 and 2.1 RRs for solid cancer, and 1.89 and 2.17 RRs for whole cancer, respectively. Conclusion The risk of liver cancer and colorectal cancer is higher for medical X-ray workers in Chongqing, and the risk of solid cancer and whole cancer is higher in the high cumulative dose group. Therefore, radiation workers should pay attention to the optimization of protection.

目的 建立简单合理的物项安全分级,以提高设施的安全性,减少营运单位和设计单位的工作量,并为核安全审评工作提供审评依据。方法 在调研国内外核燃料循环设施物项安全分级现状的基础上,进行总结和归纳。结果 通过分析,明确了当前我国核燃料循环设施的物项安全分级存在问题,就如何解决当前存在的问题提出了建议。结论 为进一步提高核燃料循环设施安全性,有必要制订相应的安全分级标准。

目的 探讨数字化床旁胸部摄影规范化操作对床旁胸片质量控制和优化的意义及临床应用。方法 数字化床旁胸部摄影使用CR,DR技术,摄影时严格按照规范化摄影程序操作,对其所得胸部正位影像各300份进行对比分析。结果 CR,DR所得图像均能满足临床诊断需求。移动DR摄影图像显示更快,图像影像清晰,甲片率和乙片率均高于CR图像,摄影所需曝光参数(kVp/mAs)明显降低约10~15kV,0.5~1mAs。结论 数字化床旁胸部摄影的合理使用和规范化操作,图像质量得到改善,能提供高质量的影像资料。移动DR能方便快捷获得数字图像,提高工作效率,降低摄影条件,减少辐射,在床旁胸部摄影中具有更高的应用价值。

To evaluate the impact of radioactive waste gas on environment or to monitor nuclear accident, the radioactive inert gas, produced both in nuclear test and nuclear power plant, need to be monitored. This study focused on the actualities of monitoring radioactive inert gas(Kr、Xe) in China, and the status of measurement traceability is summarized.Aiming to find out the deficiencies and provide some suggestions for improving the radioactive inert gas monitoring system.

Objective To analyzed the shielding effect of X-ray on protective door.Methods We calculated the dose contribution of primary and secondary scattering to the outside of the door by using the recommended formula in (GBZ/T 250-2014).Results The influence of primary scattering on the external radiation dose of the door is great, the secondary scattering has certain influence on the dose outside the door, but within the limit.Conclusion The more scattering the scattering line, the smaller the effect on the external radiation dose. Under certain conditions, the main radiation ray by the second scattering, the dose outside the door meets the standard limit of requirements.

Objective To understand the problems in the use of the standard named specifications for testing of quality control in X and γ ray stereotactic radiotherapy system(WS 582—2017), and evaluate the scientificity, rationality, applicability and operability of the standard, so as to put forward reasonable suggestions for further improving.Methods According to WS/T 536—2017, the standard was tracked and evaluated by questionnaire and field survey, and then the recovered questionnaire were reviewed and the label was corrected, At last the data was input by Excel office and the statistical analysis was carried out by SPSS 13.0.Results All units using the standard were aware of the release of the standard. The training rate of technical service institutions、manufacturers、supervision institutions and medical institutions were 71.9%、85.7%、33.3% and 43.5%, respectively. The familiarity rate of technical service institutions、manufacturers、supervision institutions and medical institutions with the standard content were 71.7%、68.1%、18.5% and 54.8%, respectively. Meanwhile, all the respondents did not grasp the chapter of X-knife, and more than half of the respondents thought that the standard test methods were feasible and practical.Conclusion The users had a high degree of recognition for the coordination of standards; The practicability of the standard and the operability of the detection method were generally recognized. Meanwhile, In the future the publicity and training efforts need to be improved, and some testing indexes and methods need examples and explanation

Skin is the first organ of contact with ionizing radiation. Radiation-induced skin injury is common because the basal cell layer and capillaries of the skin are very sensitive to radiation. Acute radiation-induced skin injury primarily involves cellular alterations and inflammation in the epidermis and dermis, and late skin injury is mainly related to the effect of radiation on blood vessels. Clinical manifestations of radiation-induced skin injury include erythema, dry desquamation, moist desquamation, and ulceration in the skin mucosa, and the severity is related to the type and dose of radiation. Currently, the underlying mechanisms of radiation-induced skin injury are largely unknown, and the gold standard for the treatment of radiation injury has not been established. The known mechanisms of radiation-induced skin injury can be roughly divided into three pathways: oxidative stress injury caused by excessive production of reactive oxygen species, inflammation triggered by transcriptional activation of cytokines, and immune response evoked by bone marrow-derived cells. This paper reviews the three major pathways of mechanisms of radiation-induced skin injury, giving a reference for further mechanism study and preventive treatment of radiation-induced skin injury.