Objective To measure and analyze Varian Clinac 21EX accelerator induced radioactivity,and to provide specific recommendations and ways of radiation protection for radiotherapy technicians.Methods To simulate the working environment of radiotherapy technician,and to detect induced radioactivity variation of Varian Clinac 21EX accelerator that induced by 15 MV X-rays under different conditions of beam field area,dose,time,distance and by high energy electron beam (12,16,20 MeV)at the different time.Results The induced radioactivity level was not influenced by different beam field area,and was increased with increasing dose (r =0.930,P ＜ 0.05),decreased with time increase (r =-0.84,P ＜ 0.05),decreased with distance increase(r =-0.975,P ＜ 0.05).The induced radioactivity attenuation levels of the different doses at the same time are different,and have the common characteristic that the induced radioactivity attenuation rate is faster in the initial times.The induced radioactivity levels of high energy electron beams were significantly lower than those of high-energy X-rays.Conclusions During radiotherapy positioning,it is necessary to take measures to protect against the induced radioactivity when high-energy rays with energy greater than 10 MeV will be used.The radiotherapy technician should take the different time and energy interval steps for the different ray type and energy and dose in order to meet the radiation protection principle of optimization.

目的 对2012年我区一名放射工作人员个人剂量监测中数据异常的原因进行调查分析,以进一步加强放射防护管理,保护放射工作人员健康.方法 使用多功能辐射防护监测仪对某核医学科环境和放射工作人员进行污染检测.结果 个人剂量监测异常升高是由于某放射工作人员体表受到放射性核素严重污染所致,其体表被污染最大值为1 676.41 Bq·cm-2,3个月个人受照剂量为1.51 mSv,高出我区2008年放射工作人员年平均剂量水平100倍.结论 加强防护知识培训,加大监督执法力度,提高个人防护意识.

目的保障公众、患者与放射工作人员的健康与安全,全面落实放射防护监督管理工作。方法依据《军队卫生监督规定》和《军队放射防护监督实施办法》,对放射工作单位实施现场监督检查。结果预防性审查工作未得到全面落实;开放型放射源使用和管理符合要求,但有1处布局不合理;密封型放射源使用管理均符合要求;按规定使用附加防护用品;放射工作人员按规定进行健康检查,进行个人剂量监测,并办理了《放射工作人员证;》各单位均按规定办理了《射线装置工作许可证》和《放射性同位素工作许可证;》按规定进行放射工作场所的监测;各单位均成立了放射防护领导机构,订立放射防护各项规章制度并得到落实。结论应进一步加强放射防护监督管理工作,确保医用辐射安全。

目的 以日本大地震核泄漏事故为警示,探索进一步加强战区“三防”医学建设的思路.方法 对日本核事故中的卫生应急措施进行文献调研,深刻反思西北地区核生化安全现状与战区“三防”医学建设现状,为进一步加强战区“三防”医学建设提出初步设想.结果 西北地区存在核生化安全隐患,战区“三防”医学硬件软件建设虽已取得全面发展,但距离形成实战保障力还存在较大差距.结论 全面推进战区“三防”医学建设,应着力做好以下工作:坚持不懈抓人才队伍建设；自主创新抓专业装备建设;紧贴实战背景抓人-装结合训练；深入开展战区核生化事故源本底调查研究；建立健全切合实战的“三防”医学救援方案；建立军地各部门通力协作的联动机制；积极做好核生化安全的宣传储备.

<正>新建放射装置的预防性审查是《军队放射防护监督实施办法》中规定的一项重要内容。2010年我中心对我区某医院一台拟装DR改建项目进行了预防性审查,该DR型号为DEFANI-UM-6000,由美国GE公司生产。

[Objectives]To evaluate the radiation safety of rotary head gamma knife and its treatment room.[Methods]The leakage radiation dose of rotary head gamma knife was detected,and the indoor and outdoor dose distribution of treatment room under the treatment condition and non-treatment condition was tested.[Results]The dose rate of various directions at 5cm away from therapy system head surface was in the range of 0.18~0.80 μGy/h,and that at 1m away from radiation source was 0.25~2.60 μGy/h.When treating,the dose rate of various measuring points outside the shielding wall of treatment room was 0.19~0.67 μGy/h.[Conclusion]The leakage radiation dose of rotary head gamma knife meets the national standard.

目的确保医疗质量和医用辐射安全。方法依据国家有关标准的规定,对一台新装旋转式头部γ刀剂量学等参数进行测试。结果按验收要求分别测试了剂量学各种参数、放射性物质的泄漏和屏蔽块的防护。结论测试结果显示旋转式头部γ刀,达到国家相关标准的要求。

目的加强放射防护管理,保护放射工作人员健康。方法依据国家和军队相关法律法规和标准。结果回顾了我辖区对放射工作人员个人剂量进行监督管理情况和存在问题,提出了加强管理的对策。结论全面加强对放射工作人员个人剂量监测与管理工作,继续提高放射卫生防护水平。

2010年4月14日,青海省玉树地区发生里氏7.1级大地震,导致生态环境和人居环境发生剧变,对病媒生物及相关传染病产生未知影响.大量的尸体腐烂、废墟垃圾、遍地瓦砾,为病媒生物的繁殖与孳生提供了有利条件.因此,灾后要防大疫,做好灾区预防性消毒和病媒生物的防治工作非常重要.

[Objective]Through the acceptance inspection of medical electron linear accelerator,to observe whether it meet the related radiation protection standards and regulations or not,so as to protect the safety of patients and the public.[Methods]Acceptance inspection was performed on medical electron linear accelerator according to the testing procedure and method of related laws standards of the army and nation.[Results]Inspection items included the control desk display,safety interlock system,protection installation,dose measurement system,operating manual and management regulation,protection monitoring and health management,safe operation requirement and so on;all items were in line with the requirements.Detection items: ①protection installation,the external radiation level of therapy room door,control house,therapy room wall was 3.6～5.53μSv/h,0.4～4.3 μSv/h,4.4～5.5 μSv/h(irradiation on main protection wall)and 0.1μSv/h(other irradiation state),respectively;②The relative divergence of monitoring system indicated value calibration was less than±3%,the reproducibility of 10 times measurement was not more than 0.7% when X-ray energy was 6,10 and 15MV respectively,meanwhile,the maximum linear deviation was not more than±2%.③ The deviation between the radiation matter and resultant given by factory was not more than ±3%,the uniformity and symmetry of the radiation field size was 1.04(6 MV)and 1.02(6 MV) respectively,the ratio of the permeation beam limiting device X-ray leakage absorbed and useful track group central axis maximum absorbed dose was 0.02%,the permeation beam limiting device X-ray maximum leakage absorbed dose and average leakage absorbed dose occupied 0.0012% and 0.00063% of maximum absorbed dose respectively.④The rotation center deviation of stander,collimating device,treatment couch was less than 1mm respectively.[Conclusion]Through the comprehensive inspection and detection on the medical electronic linear accelerator of technical characteristics,protection function,protection facilities of the therapy treatment,monitoring and management of radiation protection and so on,it indicates that the radiotherapy work can be commenced owing to the radiation protection consistent with the related standards.

[Objective]To understand the individual dose level and protection status of radiation workers in Lanzhou military region,so as to further strengthen the radiation protection management and protect the health of radiation workers.[Methods]BR2000D thermoluminescence dosimeter and thermoluminescence individual dosimeter were applied to conduct dose monitoring on the radiation workers.[Results]Totally 454 people's individual dose of external exposure were monitored from 2004 to 2008,annual average dose equivalent was 0.015～0.39 mSv,the total collective dose equivalent was 77.079 man.mSv.Exposure dosage level of radiological diagnosis,radiotherapy and nuclear medicine workers was descending gradually.[Conclusion]The protection work has been strengthened obviously,and the protection condition has improved significantly in last 5 years.The compulsive dose monitoring should be carried out to some unit and individuals.In order to raise the radiation hygiene protection level,the radiation workers should be trained with protection knowledge.

目的适应部队放射卫生工作的发展形势,建立健全军区放射卫生防护体系。方法按照国家相关的法规与标准及军队的有关规定。结果设立机构、落实人员并不断改进与完善。建立起军区完备高效的放射卫生监督监测管理体系。结论全面高效的监督监测管理体系,是提升放射卫生水平的根本保证。

目的 通过放射防护预审使医院新建的立体定向伽玛射线全身治疗系统化要求.方法 根据相关辐射标准和资料,对某医院肿瘤治疗中心立体定向伽玛射线全身治疗系统项目的 机房选址、布局和防护设计进行放射防护的预审和评价,运用剂量率仪对相关工作场所进行放射性水平监测,对其放射防护效果进行验证.结果 经过实践论证(专家评审及项目竣工验收),该立体定向伽玛射线全身治疗系统在机房选址、布局和防护设施符合有关标准和规定的要求.结论 放射单位严格按照国家有关法规标准设计建设大型医用射线项目的 同时,加强设计预审与放射防护效果验证,对于消除项目隐患、节省建设经费,提高放射诊疗质量和保证防护安全具有深远的意义.

目的通过对放射工作场所基建项目进行预审,使伽玛刀基建项目达到国家和军队有关标准要求,保障放射工作人员和广大公众的健康与安全。方法根据国家《电离辐射防护与辐射源安全基本标准》等规定要求进行预防性审查。结果使基建设计达到防护最优化原则,减少迷道墙、南墙和西墙厚度。结论该中心的选址,放射防护设计,管理措施等,符合国家有关放射防护规定和标准的要求,是可行的。

目的对立体定向伽玛射线全身治疗系统治疗室的防护设计进行预防性审查,以保证各类人员受照剂量在规定限值以内,并符合最优化原则要求。方法依据设计图纸、治疗室准备采用的建筑材料和伽玛射线全身治疗系统源项等内容,根据不同方向射线距离平方反比衰减关系和防护屏蔽材料衰减系数进行防护屏蔽厚度的计算,要求控制在《电离辐射防护与辐射源安全基本标准》范围之内,并留有二倍安全系数。结果迷道墙和南墙的厚度应为0.6m,西墙的厚度应为0.9m。结论通过计算和分析,迷道墙和南墙的厚度可由设计的1m减少至0.6m,西墙的厚度可由设计的1m减少至0.9m,这样既可达到防护的最优化目标,又可节省经费开支和扩大工作空间。

目的对兰州军区医疗卫生单位医源性辐射的设备防护性能、射线产生的自由基对DNA损伤、放射工作人员个人剂量监测和放射防护管理等方面进行研究和实践,旨在提高辐射防护水平和质量。方法按照国家相关标准进行放射工作场所辐射防护监测;采用军事医学科学院研制的诊断X射线机质量保证检测箱进行质量保证检测。根据《军队放射防护监督实施办法》进行辐射防护监督管理。结果对62台不达标X射线机进行防护改造,超标点由原来的79%下降至改造后的10.4%。军区医用诊断X射线机房防护状况进行监测。质量保证监测了22台医用诊断X射线机中,除进口的1台摄影机及1台透视机全部指标合格外,其余的均有一项或数项指标未达标。射线产生的自由基使DNA合成持续抑制,为不可恢复的模板型损伤。结论通过长期监督监测,兰州军区放射工作场所环境防护有了较大的改善;诊断X射线机质量保证质量控制水平有待进一步提高。

根据<军队卫生监督规定>、<军队放射防护监督实施办法>的要求,我中心在2006年对我区医疗卫生单位进行了放射卫生防护监督监测.

医用诊断X射线机影像质量保证、质量控制中管电压的准确性作为一个重要指标直接影响诊断效果,为此我们对我区某中心医院诊断X射线机进行了管电压测试.

氡普遍存在于我们的生活环境中,氡的辐射剂量约占天然辐射剂量的一半.ICRP 50号出版物估计公众肺癌的10%归因于氡及其子体照射.为了解兰州地区各类房屋中氡的水平,笔者于2001至2003年对兰州市普通居民住宅室内氡浓度进行了调查.兰州市位于甘肃省的中部,地处东经103°30′～104°30′,北纬35°35′～37°10′面积为14 000 km2.北靠武威地区,西界青海省,西南接临宁夏回族自治州,东部邻定西地区.大部分地区被黄土所覆盖,是黄土高原的西北部.海拔一般为1500～2000 m.全市主要为山地、半山地、河川等类型,其中山地占全市面积65%.

在进行放射防护监督监测时,往往有人问及:到底多厚的铅板才能完全对射线进行防护.在此可应用量子力学原理进行诠释.