基于QA BeamChecker Plus对加速器的日常质量保证  

Linear Accelerator base on QA BeamChecker Plus

作　　者：吴丽丽[1] 陈泓[1] 林浩[1] 

机构地区：[1]汕头大学医学院附属肿瘤医院放疗科,广东汕头515031

出　　处：《医疗装备》2014年第5期16-18,共3页Medical Equipment

摘　　要：目的:通过分析照射野剂量参数的日常质量保证数据,探讨直线加速器照射野日检方法的可行性和必要性。方法:每天放射治疗前,用平行板电离室矩阵QA BeamChecker Plus(QABC+)测量加速器照射野相关参数与基准值的偏差,并对数据进行系统性分析,辅以二维电离室矩阵MatriXX进行平坦度和对称性的二次验证,评价指标包括中心轴剂量、平坦度、对称性。评价标准如下:剂量输出偏差≤±2%,平坦度偏差≤1%,对称性偏差≤±1%。结果:5个月的QABC+日常质量保证结果显示,6MV-X线的剂量输出稳定性合格率为99%,射野平坦度和轴向对称性基本保持不变;横向对称性偏差合格率为85.3%,与MatriXX测量结果一致。结论:基于质控设备QABC+的照射野日检方法是有效和可行的,它在保证每日放疗精确执行的同时,也为加速器的长期质量保证提供了依据。Objective： To evaluate the clinical feasibility of daily quality assurance for linac radiation field by analyzing the trend of the daily quality assurance data. Methods： Parallel ion chamber array QA BeamChecker Plus （ QABC ＋ ） was used to measure dosimetric filed parameters changed frombaseline before daily treatment. MatriXX was also used to measure the filed flatness and symmetry monthly. Dosimetric parameters, including output, flatness and symmetry, were employed to evaluate the dose delivery constancy of linacwith the tolerancesineluding： output constancy ≤± 2%, flatness constancy ≤±1%, symmetry constancy ≤± 1%. Result： QABC ＋ Daily QA resuhsshowed that the dose output deltapassing rate was 99%. The constaneyof flatness and axial symmetry were ex- cellent. Thepassiug rateof transverse symmetywas 85.3%, in line with the MatriXX results. Conclusion： The procedures for daily quality assurance of linae radiation field are feasible in our experience, and it will provide systematicbasis for long term linae quality as- surance.

关 键 词：加速器 质控设备 QA BeamCheckerPlus 日常质量控制 

分 类 号：R197.39[医药卫生—卫生事业管理]