ArcCheck系统在鼻咽癌容积旋转调强剂量验证中的应用

Dosimetric Verification of Volumetric Modulated Arc Therapy in Nasopharyngeal Carcinoma using ArcCheck System

目的:研究ArcCheck验证系统在鼻咽癌容积旋转调强剂量验证中的应用。在病人接受放射治疗之前,进行容积调强计划的验证,使其满足计划设计要求。保证患者实际照射中接受到准确的剂量,确保治疗的安全。方法:选择34例鼻咽癌病例用热塑型体部网罩固定,CT扫描定位,将计划CT传到Pinnacle计划系统(9.2版本)中进行容积旋转调强治疗计划设计,然后将设计好的计划传输至MOSAIQ网络系统上。同时把治疗计划导入ArcCheck模体中重新新型剂量计算。在验证之前,对Arccheck系统进行本底校准,矩阵校准,绝对剂量校准。分析方法采用的是Gamma方法在ArcCHECK自带软件中对治疗计划系统中计算的结果和实际测量的结果二者的差异,阈值标准选择3%,3mm,10%。采用微软Excel2003数据统计软件。结果:Gamma分析方法相对量通过率97.9%,绝对量通过率为95.9%;实测剂量分布图与理论计算剂量分布图在高低剂量点分布上重合很好;另外X方向和Y方向的平坦度,实测结果与计算结果很接近。结论:ArcCheck验证系统在鼻咽癌容积旋转剂量验证中是可行的。它是一种方便快捷准确的旋转调强剂量验证方法。

Objective：To investigate the dosimetric performance of ArcCHECK system,to validate the designed plan before patients radiotherapy,to make sure patient gain accuracy dosimetry.Methods：34 VMAT treatment plans of nasopharyngeal carcinoma patients were performed with Pinnacle treatment planning system（TPS）,and then these plans were exported to MOSAIQ system,treatment plans were transplanted into ArcCHECK phantom and recomputed.Calibrated Arccheck system,matrix and absolute dose Before validation.Usingbuild-in the ArcCHECK software to analyze the result.Comparison of Pinnacle calculated dose versus the real measured result by Gamma methods,which threshold were 3mm,3%,10%,statistics software is Microsoft Excel 2003.Results：The relative dosage pass rate was 97.9%,and the absolute dosage pass rate was 95.9%.The measured and calculated dose distribution and the profile of X and Y direction is also coincided with the actual measured and calculated dose distribution.Conclusions：The Arc CHCK system was an ideal tool for the VMATverification.