三维剂量验证系统Delta4在容积旋转调强计划剂量验证中的应用

Application of 3D Dosimetric verification system Delta4 for VMAT verification

目的:探讨三维剂量验证系统Delta4对容积旋转调强计划进行剂量验证的可行性。方法:利用Delta4对20例患者的容积旋转调强计划进行剂量验证;为了对比,同时用MatriXX电离室矩阵对相同计划的冠状面进行剂量分布验证;利用剂量仪、指形电离室对相同计划进行点剂量的绝对剂量验证;将三种方法的验证结果进行比对。剂量分布验证采用Gamma分析,取剂量3%、距离3mm,通过率≥95%为验证通过标准。结果:三种验证方法所有计划的误差均在允许范围之内。使用Delta4验证治疗计划的Gamma通过率平均为98.90%,各个射野的Gamma通过率平均99.83%;用MatriXX电离室矩阵验证各计划冠状面剂量分布Gamma通过率平均为98.02%;绝对剂量验证平均误差为1.18%。结论:利用Delta4对旋转容积调强计划进行剂量验证是可行的。

Objective： To discuss the application of 3D dosimetric verification system Delta4 for VMAT verification. Methods： Evaluation the dosimelrie verification of VAMT plans of 20 patients with Delta4; For comparison, the Coronal plane does of the same plan were measured with MatriXX ionization chamber array; the absolute does of the same plan were measured with dosimeter and ionization chamber. Compare the results of the three methods. The results of the dose distribution were analyzed by Gamma analysis, with dose 3%, distance 3ram, the criterion of a successful verification is that the passing ratio reaches greater than 95%. Results： The errors of the three methods all within the allowance range. The overall average percentages of passing ratio measured with Delt4 for the plan and each field is 98.90% and 99.83%, respectively; The overall average percentages passing ratio measured with MatriXX and the average errors of the absolute does is 98.02% and 1.18%,respectively. Conclusions： The application of 3D dosimetric verification system Delta4 for VMAT verification is practicable.