IC Profiler性能研究

Performance Research of IC Profiler

目的通过比较IC Profiler与三维剂量分析仪的测量结果,研究IC Profiler的性能。方法使用IC Profiler与三维剂量分析仪分别测量6 MV X射线、10 MV X射线、6 MV FFF(FFF:Flattening Filter Free,射线束没有被匀整过滤)X射线和10 MV FFF X射线的平坦度、对称性、射野宽度、半影、中心点,对两种设备的测量结果进行对比分析,将IC Profiler测量值减去三维剂量分析仪测量值,得出两者差值数据。结果用IC Profiler测量的射野平坦度结果比使用三维剂量分析仪稍小。对比测量FF和FFF不同大小射野的对称性,IC Profiler均与三维剂量分析仪测量值差别很小,符合度好,可以用于测量所有射野的对称性。射野宽度测量中,用IC Profiler测量的数值比三维剂量分析仪测量值稍小,差别均值为1.3 mm。IC Profiler半影测量值较小,与三维剂量分析仪结果差别较大。射野中心的测量,两种方法差别较小。结论 ICProfiler不宜测量照射野半影;测量射野的宽度会产生2～3 mm的误差;测量射野平坦度、对称性、射野中心位置,与三维剂量分析仪相一致。在快速检查射野性能、调试加速器时,IC Profiler是一个较好的工具。

Objective By comparing the measurement results of IC Profiler with 3D dose analyzer,the performance of IC Profiler was investigated.Methods The flatness,symmetry,field width,penumbra,and center point of 6 MV X-ray,10 MV X-ray,6 MV FFF X-ray,and 10 MV FFF X-ray were measured and compared using IC Profiler and 3D dose analyzer,respectively.The differences of the measured values between two instruments were calculated.Results The field flatness measured with IC Profiler was slightly smaller than that obtained with the 3D dose analyzer.By comparing the symmetry of FF and FFF with different field sizes,the difference between two instruments was very small,with a good coincidence degree.IC Profiler can be used to measure the symmetry of all fields.In the field width measurement,the value measured by IC Profiler was slightly smaller than that measured by the 3D dose analyzer,with a mean difference of 1.3 mm.In the penumbra measurement,the IC Profiler showed a small measurement value,which was quite different from the 3D dose analyzer.There were small difference of center point measurement between two instruments.Conclusion IC Profiler is not suitable to measure the penumbra of the radiation field.Field width measurement using IC Profiler will produce an error of 2~3 mm.The measurement values of the field flatness,symmetry,and center position of the field obtained from IC Profiler are consistent with that from 3D dose analyzer.IC Profiler is a good tool for rapid inspection of field performance and debugging accelerators.