三维水箱测量系统在超长服役直线加速器质控中的应用

目的:利用三维水箱对超长服役直线加速器进行质控,分析实施过程和质控结果,以更好地监测加速器的性能,保障临床治疗的准确性。方法:收集2017年7月至今的Elekta Synergy直线加速器月检质控数据。测量使用德国PTW公司生产的三维水箱系统,共计26组有效数据。采用机器验收标准分析输出数据,6MV、10MV能量射线平坦度标准参考值为100%±6%、对称性标准参考为100%±3%。6MV、10MV能量X射线质参考值分别为67.5%、73.0%,误差允许范围为±2%。记录每次水箱架设时间。分析其中出现的非理性现象。结果:Y、X轴方向,6MV能量射野平坦度测量误差为4.01%±0.44%、4.93%±0.44%,对称性测量误差为0.76%±0.35%、0.95%±0.43%;10MV能量射线平坦度测量误差为3.53%±0.72%、5.07%±0.59%,对称性测量误差为0.79%±0.32%、1.31%±0.66%。6MV、10MV射线质测量误差为0.59%±0.26%、1.36%±0.44%。6MV、10MV能量射线平坦度、对称性、射线质测量结果均在误差允许范围内。水箱从架设到调试成功的时间为(37.19±6.89)min。结论:测量结果表明,在严密的质控实施下,加速器运行状况良好。

Use of Three-Dimensional Water Scanning System in Quality Control of Long Service Linear Accelerator

Objective:To monitor the long service linear accelerator for accurate clinical treatment by using the three-dimensional(3 D)water scanning system.Methods:The monthly tested data of Elekta Synergy Medical Linear Accelerator from July 2017 up to the present were collected and measured using the PTW 3 D water scanning system for a total of 26 valid datasets.The acceptance criteria was used to analyze the output data.The standard reference value of flatness was 100%±6%,and the symmetry was 100%±3%for 6 MV,10 MV energy X-ray.The X-ray quality reference values of 6 MV,10 MV energy were 67.5%and 73.0%,respectively,and the tolerance range was±2%.The time of 3 D water tank erection was recorded.Results:The flatness,symmetry,and ray quality reference measurement results of 6 MV,10 MV energy ray were within the allowable error range.In the Y and X directions,the measurement errors of the 6 MV energy field flatness were 4.01%±0.44%and 4.93%±0.44%,and the measurement errors of symmetry were 0.76%±0.35%and 0.95%±0.43%;the measurement errors of the 10 MV energy ray flatness were 3.53%±0.72%and 5.07%±0.59%,the measurement errors of symmetry was 0.79%±0.32%and 1.31%+0.66%.The measurement errors of 6 MV and 10 MV ray quality were 0.59%±0.26%and 1.36%±0.44%.The time from tank erection to commissioning success was(37.19±6.89)min.Conclusion:The quality control of the 3 D water tank are well assured,and the accelerator works well.