基于IEC标准的医用电子直线加速器放射防护性能检测研究

发布时间：2018-01-02 00:12

本文关键词：基于IEC标准的医用电子直线加速器放射防护性能检测研究　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：目的对初次安装后的6MV医用电子直线加速器放射防护性能进行检测与分析,了解其是否符合IEC相关标准的要求,以确保加速器设备的出厂质量,保障临床放疗工作人员、患者和周围公众的辐射安全。基于发展需求,比较国家标准与IEC标准的接轨情况,确定当前的加速器质量控制检测实践,并提高关键性能指标的认识,为今后依据IEC标准检测同类设备提供有意义的借鉴。方法选取该领域典型标准,对IEC 60976:2007、IEC/TR 60977:2008、IEC60601-2-1-2014与GB 15213-1994、GB/T 19046-2013、GB9706.5-2008及其相关标准进行结构和内容的比较,以一台6MV的医用电子直线加速器为研究对象,按照标准要求并查阅设备厂家验收手册,检测加速器的放射防护性能,将现场测量获得的结果与标准要求限值进行分析比较。结果(1)该医用加速器性能结果:重复性0.08%,线性0.36%,随设备角度位置的变化的关系0.42%,随机架旋转的变化关系-0.46%,随幅射野的变化关系1.20%,高剂量辐照后的稳定性为0.74%,日稳定性1.08%,周稳定性1.29%,移动束治疗的稳定性1.62%,品质指数为0.59,10cm′10cm野相对表面剂量为52.70%,最大辐射野(27cm′27cm)相对表面剂量为58.71%,5 cm′5 cm辐射野的均整度:X 103.9%、Y 103.1%,10 cm′10 cm辐射野的均整度:X 105.9%、Y 105.0%,27cm′27 cm辐射野的均整度:X 106.0%、Y 105.5%,5 cm′5 cm辐射野的对称性:X101.5%、Y 100.3%,10 cm′10 cm辐射野的对称性:X101.3%、Y 100.4%,27cm′27 cm辐射野的对称性:X 101.4%、Y 100.7%,最大吸收剂量比102%,5 cm′5 cm辐射野的半影7.9 mm,10 cm′10 cm辐射野的半影9.0 mm,20 cm′20 cm辐射野的半影10.5 mm,≤20 cm′20 cm辐射野数字指示1.0mm,20 cm′20 cm辐射野数字指示-2.0mm,≤20 cm′20 cm辐射野光野指示2.0mm,20 cm′20 cm辐射野光野指示2.0mm,光野中心与辐射野中心最大距离1.0mm,对边平行度的最大角度偏差0.3°,临边垂直度的最大角度偏差0.5°,辐射束轴的等中心偏移、治疗床、机架和限束装置等中心的指示范围0~0.5mm,沿辐射束轴的距离指示-0.5mm,前后辐射野的重合性0.5mm,治疗床的垂直运动1.0mm,治疗床的等中心旋转0.5mm,治疗床旋转轴的平行度0°,治疗床的纵向刚度1mm,治疗床的横向最大位移0~0.5mm。(2)该医用加速器防护性能结果:该医用电子直线加速器设备及操作的安全联锁系统检测内容符合标准要求;27cm′27cm野相对表面剂量为58.71%;患者平面上M区内X射线泄漏辐射率最大值为1.34%,X、Y光阑不同组合条件下测量其平均值分别为0.21%、0.26%,多叶光栅的片间泄漏辐射率最大值为3.46%;M区外最大泄漏辐射组合条件为机架0°,限束系统0°,其X射线泄漏辐射率最大值为0.11%,平均值为0.08%;患者平面外X射线泄漏辐射率最大值为0.25%,热发射管等设备部件环境剂量当量率最大值为0.08μSv/h。结论(1)该医用电子直线加速器的剂量监测系统、深度吸收剂量特性、辐射野的均匀性、辐射野的指示、等中心、沿辐射束轴的距离指示、旋转运动标尺的零刻度位置、前后辐射野的重合性、治疗床的运动等结果符合IEC 60976:2007、IEC/TR 60977:2008标准的性能要求。(2)该医用电子直线加速器其治疗体积内不正确吸收剂量的防护,辐射野内杂散辐射的防护,患者平面上辐射野外的辐射防护,患者和其他人员的辐射防护均能达到IEC 60601-2-1标准的防护要求。(3)IEC标准更新及时且内容全面,在产品的安全性能方面要求极为严格,有些技术性能参数检测难度大,放射防护性能检测项目繁多,本研究涉及的国家标准采用IEC标准,章条名称和编排顺序基本一致,我国应合理设定QC测试频率,以确保适当性、实用性和操作性。我国应加大采用国际标准的力度,应进一步加强放射卫生标准体系中此类标准的制修订工作,以期有价值的方法得到推广。
[Abstract]:Objective to detect and analysis the 6MV linac radiation protection performance after installing, understand their compliance with the IEC standard, to ensure the quality of equipment security staff accelerator, clinical radiotherapy, patients in and around public radiation safety. Based on the requirements of the development of standards is the national standard and IEC standard the accelerator is determined the current practice of quality control, and improve the understanding of the key performance indicators, according to the IEC standard for future testing of similar equipment to provide a meaningful reference. Methods in the field of typical standard, IEC 60976:2007, IEC/TR 60977:2008, IEC60601-2-1-2014 and GB 15213-1994, GB/T 19046-2013, compare the structure and content of GB9706.5-2008 and its related the standard, with medical electron linear accelerator with a 6MV as the research object, in accordance with the standard requirements and inspection equipment manufacturers The acceptance test manual detection, radiation protection performance of the accelerator, the field measurement results obtained with the standard limit value were analyzed and compared. Results (1) the medical accelerator performance results: repeatability of 0.08%, 0.36% and 0.42% linear, variation of angular position equipment, random frame rotation changes between -0.46%, with 1.20% changes the radiation field, the stability of high dose irradiation for 0.74% days, 1.08% week 1.29% stability, stability, stability of 1.62% moving beam therapy, quality index for 0.59,10cm '10cm wild relative surface dose is 52.70%, the maximum radiation field (27cm' 27cm) relative surface dose of 58.71%, 5 'cm 5 cm radiation field are finish: X 103.9%, Y 103.1%, 10 cm' 10 cm radiation field flatness were: X 105.9%, Y 105%, 27cm '27 cm radiation field are all: X 106%, Y 105.5%, 5 cm' 5 cm radiation field symmetry: X101.5%, 100.3% Y, 10 cm '10 cm Radial symmetry field: X101.3%, Y 100.4%, 27cm '27 cm radiation field symmetry: X 101.4%, Y 100.7%, the maximum absorbed dose ratio of 102%, 5' cm 5 cm radiation penumbra 7.9 mm, 10 cm '10 cm radiation penumbra 9 mm, 20 cm' 20 cm radiation field the penumbra is 10.5 mm, less than 20 of CM '20 cm radiation field digital indicator 1.0mm, 20 cm' 20 cm radiation field digital indicator -2.0mm, less than 20 of CM '20 cm 2.0mm cm 20 indicating radiation No Hikaruno, No Hikaruno' 20 cm radiation 2.0mm indicator light field center and radiation center of the maximum distance of 1.0mm, the maximum angle of edge parallelism deviation of 0.3 degrees, the maximum angle deviation near 0.5 degrees vertical axis of the radiation beam, etc. center offset treatment bed, indicating the range of 0~0.5mm frame and beam limiting device such as the center, along the axis of the radiation beam indicating the distance -0.5mm, the coincidence of 0.5mm before and after the radiation field, the vertical movement of 1.0mm treatment bed so, the center of the rotating bed treatment 0.5mm treatment bed rotary shaft parallelism of 0 degrees, the longitudinal stiffness of 1mm treatment bed, the maximum lateral displacement 0~0.5mm. treatment bed (2) of the medical accelerator protective performance results: safety interlock system to detect the linac equipment and operation in accordance with the standard requirements; 27cm '27cm wild relative surface dose for the 58.71% patients; plane area M X ray radiation leakage rate maximum value is 1.34%, X, Y diaphragm under different combinations of measuring the average values were 0.21%, 0.26%, a multi blade grating between radiation leakage rate maximum value is 3.46%; M outside the leakage radiation combination conditions for frame 0 degrees that limit beam system of 0 degrees, the X ray radiation leakage rate maximum value is 0.11%, the average value is 0.08%; with the out of plane X ray radiation leakage rate maximum value is 0.25%, the heat tubes and other equipment components of environmental dose equivalent rate to a maximum of 0.08 Sv/h. conclusion (1) the medical electric Dose monitoring system of sub linear accelerator, depth absorbed dose characteristics, uniformity of radiation field, radiation field instructions, such as the center, along the beam axis distance indicator, the zero position rotation scale, before and after the radiation coincidence of the wild, the treatment bed movement results meet the performance requirements of IEC/TR 60977:2008 IEC 60976:2007. Standard. (2) the medical accelerator treatment volume protection incorrect dose, radiation protection field stray radiation protection, radiation field with plane, radiation protection protection of patients and other personnel are able to meet the requirements of 60601-2-1. IEC (3) IEC standard updated in a timely manner and content overall, in terms of product safety performance requirements are extremely strict, some technical parameters of the detection difficult, various radiation protection performance testing project, this study involves the national standard with IEC standard Chapter one, the name and the order of the arrangement is consistent, our country should set reasonable QC testing frequency, to ensure the appropriateness, practicality and maneuverability. China should increase the use of international standards efforts, should further strengthen the revision of such standard radiological health standard system, so as to obtain valuable promotion.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R142

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