Verification of the range calculation accuracy of a commercial proton treatment planning system
10.3760/cma.j.cn113030-20220107-00009
- VernacularTitle:商用质子治疗计划系统射程计算精度的验证
- Author:
Xiangshang SUN
1
;
Yuehu PU
;
Wentao LIAO
;
Haiyun KONG
;
Mei CHEN
;
Chao WU
;
Nan YAN
;
Chaofan AN
;
Junya LIU
Author Information
1. 中国科学院上海应用物理研究所，上海 201800
- Keywords:
Proton therapy;
Treatment planning system;
Calculation accuracy
- From:
Chinese Journal of Radiation Oncology
2022;31(11):1028-1033
- CountryChina
- Language:Chinese
-
Abstract:
Objective:In Shanghai Advanced Proton Therapy Facility (SAPT) of Ruijin Hospital Proton Therapy Center, the calculation accuracy of the commercial proton treatment planning system RayStation (V10), especially the accuracy of the proton range calculation, was measured and verified, aiming to provide reference for the clinical application of the treatment planning system.Methods:A head phantom was used to verify the calculation accuracy of RayStation. The phantom CT was imported into treatment planning system (TPS). The phantom was followed closely by a water tank with a one-liter cubic target. A single field verification plan with the prescribed dose of 200 cGy (relative biological effectiveness) was designed and implemented. Then, the measured distribution results were compared with the calculation results.Results:When the verification plan of the phantom was designed with the default settings of RayStation, the measured longitudinal dose distribution was approximately 4 mm deeper than that of TPS, indicating that RayStation overestimated the water equivalent thickness (WET) of the tissue substitute materials in the phantom. To study the range error, the actual beam was used to measure the WET of the soft tissue substitute material. The default setting of RayStation was fine-tuned according to the measured results. It was found that the error between the measured SOBP and TPS calculations was reduced to only 2 mm.Conclusions:Using the default setting of RayStation to calculate the stopping power of the phantom may cause a large range error. A method that combines tissue segmentation with the measured WET of the tissue substitute material is proposed to improve the range calculation accuracy of the TPS. The results show that the proposed method can improve the dose and range accuracy of the commercial TPS including RayStation for tissue substitute materials.
