国产加速器IMRT和VMAT的剂量学测试

目的应用TG119报告中的测试例对联影公司URT-Linac 506C加速器和URT计划系统FF模型进行全面的评估。方法主要研究调强放疗(IMRT)和容积调强弧形治疗(VMAT)计划剂量目标、点剂量和剂量分布计算准确性。测试模体采用AAPM TG119号报告测试例模体,主要包括模拟多靶区、模拟前列腺肿瘤、模拟头颈肿瘤和模拟C形靶区(简单)等。使用指形电离室和胶片,在URT计划系统(临床实验版本)和URT-Linac 506C加速器上分别优化计算和测量剂量,并分析计划剂量和测量值之间的偏差。结果URT计划系统中的4个测试案例的计划剂量目标均满足TG119标准要求。对于不同案例点剂量验证,IMRT计划最大误差为2.62%,VMAT计划最大误差为3.90%,均满足TG119报告中点剂量误差小于4.5%的要求。复合剂量分布胶片测量结果的γ通过率IMRT计划均>97.50%,VMAT计划均>93.27%。结论URT-Linac 506C加速器和URTT放疗计划系统FF计算模型性能试验结果均达到TG119报告验证标准。

Dosimetry test of domestically-made accelerator intensity-modulated radiation therapy and volumetric-modulated arc therapy

Objective To create AAPM TG 119 test plans for intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) in order to evaluate the accuracy of the United Imaging Healthcare's URT treatment planning system (URT-TPS). The plans were delivered to the phantom using the United Imaging Healthcare's URT-Linac 506C. Methods The overall accuracy of IMRT and VMAT planning, measurement, and analysis were evaluated for four test geometries provided by American Association of Physicists in Medicine (AAPM) Task Group Report 119(TG-119) on multi-target, prostate, head and neck and C-shape (easy). The dose distributions were measured in the coronal plane. The point measurements were measured by a Farmer type ion chamber and fluence measurements were completed with film and Delta4 phantom, respectively. Measured planar dose distributions were analyzed using gamma index with criteria 3%/3 mm. Results For IMRT and VMAT plans, the planning results matched the TG-119 planning results. Measured point doses of IMRT and VMAT were within 2.62% and 3.90% of the planned doses, respectively. Measured film dosimetry gamma values of IMRT and VMAT were> 97.50% and> 93.27%, respectively. Conclusion Based on these analyses which were performed in line with the TG119 recommendations, it is evident that the URT treatment planning system and URT-Linac 506C have commissioned IMRT and VMAT techniques with adequate accuracy.