使用两种方法评价鼻咽癌调强计划的rPortal Dosimetry剂量验证结果

摘要

Objective To perform dose verification for intensity-modulated radiotherapy (IMRT) plans of nasopharyngeal carcinoma (NPC) with the Varian Portal Dosimetry (PD) system, and evaluate the dose verification Results by two Methods .Methods A total of 16 PD verification plans of NPC were selected to analyze the data by two Methods . Method 1, statistical analysis was applied to data of gamma passing rate of all fields for each PD verification plan. Method 2, for each PD verification plan, the total field was obtained by matrix superposition, and gamma analysis was applied to each total field. Results There were 278 fields for the 16 PD plans, and the statistical value (mean±standard deviation) of the gamma passing rate was 98.73%±1.66%. There were 97.12% of the total 278 fields with gamma passing rate higer than 95%. For each PD verification plan, the mean value of gamma passing rate of all fields was higher than 97%. For the 16 PD verification plans, statistical analysis was also applied to the data of gamma passing rate of the total field, the mean value of gamma passing rate was 96.05%±2.01%. There was statistical difference by comparing the mean values of gamma passing rate of all fields for each verification plan and the values of gamma passing rate of the total field.Conclusion From analyses of the two Methods , it could be seen that, Results of PD dose verification for the 16 IMRT plans of NPC are good. It indicates that the parameter delivery and treatment implementation for the IMRT plans ware accurate. By using a combination of the above two Methods , the PD dose verification Results of IMRT plans could be analyzed in depth.%目的 使用瓦里安Portal Dosimetry(PD)系统对鼻咽癌调强放疗计划进行剂量验证,使用两种方法 对验证结果 进行分析与评价.方法 选取16例鼻咽癌PD验证计划的数据,使用两种方法 进行分析评价.方法 1,对每一例验证计划所有射野的Gamma通过率数据进行统计分析;方法 2,对每一例验证计划,通过矩阵相加的方法 得到总射野,对总射野进行Gamma分析.结果 16例鼻咽癌PD验证计划共计有278个射野,所有射野的Gamma通过率(平均值±标准差)为98.73%±1.66%;Gamma通过率超过95%的射野数目占总射野数目的 97.12%;每一例验证计划所有射野Gamma通过率的平均值大于97%.对16例PD验证计划总射野的Gamma通过率进行统计分析,平均值为96.05%±2.01%.对所有验证计划,比较每例计划所有射野Gamma通过率的平均值与计划总射野的Gamma通过率值,两组数据有统计学差异.结论 由两种评价方法 的分析可见,16例鼻咽癌调强计划PD剂量验证结果 总体较好,表明计划参数的网络传输和治疗实施比较准确.综合运用这两种方法 ,可对调强计划的PD剂量验证结果 进行全面评价.