摘要
目的利用二维电离室矩阵和动态治疗日志文件,评价动态多叶准直器(MLC)滑窗技术的剂量学稳定性和机械精度。方法基于滑窗技术设计5种动态射野A、B、C、D、E,重复按照5种射野对二维电离室矩阵MatriXX进行照射并分别记录其动态日志文件,对12次的测量数据进行统计分析。结果各相应照射野等中心点剂量重复性分别为±1.49%、±1.12%、±1.12%、±1.07%、±1.07%,最大相对标准偏差为±1.47,γ分析通过率(3%/3mm)均为100%;动态治疗日志文件显示所有叶片定位误差均<0.05cm,定位误差的标准差均值分别为0.0365、0.038、0.038、0.035、0.026cm。结论本实验中动态MLC剂量学稳定性和机械精度满足治疗要求,本方法简单方便,可作为常规MLC质量保证程序的补充。
Objective We estimated dosimetric and mechanical accuracy of sliding window in dynamic intensity-modulated radiotherapy with a 2D diode array and dynalog file. Methods Five kinds of MLC format files based on sliding window technique were designed. 2D array of MatriXX was radiated in the linac and dynalog files were generated twelve times. Measured data was analyzed. Results All the repeatability errors of isocenter point dose of every fields were ± 1.49%,± 1.12%, ± 1.12%, ± 1.07%,± 1.07%, respectively. The maximum of relative standard deviations were ±1.47. All of γ- analyze pass rates were 100%. Dynalog file indicated that all leaf deviations were less than 0.5mm. The averages of errors RMS were 0.0365, 0.038, 0.038, 0.035, 0.026cm, respectively. Conclusion The result of the present work reveals the ideal functioning of the linac for dynamic dose delivery. This method is simple and convenient, which can be introduced into routine QA procedure for MLC.
出处
《中国医疗设备》
2011年第10期21-24,共4页
China Medical Devices
基金
广东省科技计划项目(2010B031600146)
广州医学院博士留学回国人员基金项目(2010-1-11)
关键词
直线加速器
多叶准直器
滑窗技术
剂量仪
调强放疗
linear accelerator
multi-leaf collimator
sliding window technique
dosimeter
intensitymodulated radiotherapy therapty
