Analysis of dosimetric verification results of three verification systems for stereotactic body radiation therapy
10.3760/cma.j.cn112271-20220624-00267
- VernacularTitle:三种验证设备在立体定向放射治疗的剂量验证结果分析
- Author:
Fan WU
1
;
Bin TANG
;
Feng YANG
;
Junxiang WU
Author Information
1. 四川省肿瘤医院·研究所 四川省癌症防治中心 电子科技大学医学院放射肿瘤学四川省重点实验室，成都 610041
- Keywords:
Stereotactic body radiation therapy;
Dosimetric verification;
Target volume;
Calculation grid size;
Dose threshold
- From:
Chinese Journal of Radiological Medicine and Protection
2022;42(9):678-684
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To compare the effects of parameters, such as planning target volume (PTV), calculation grid size, and dose threshold, on the dosimetric verification result of three dosimetric verification systems ArcCHECK, SRS MapCHECK, and 3DMap for stereotactic body radiation therapy (SBRT).Methods:Based on the dosimetric verification result of the SBRT plans of 50 patients, this study compared the effects of PTV (<25 cm 3 and ≥25 cm 3), calculation grid size (1.0, 1.5, and 2.0 mm), and dose threshold (5%, 10%, and 15%) on the γ passing rates of the three dosimetric verification systems at five criteria, i. e., 3 mm/3%, 3 mm/2%, 3 mm/1%, 2 mm/3%, and 2 mm/2%. Results:The changes in PTV affected 3DMap more significantly. With an increase in PTV, the γ passing rates of 3DMap at the criteria of 3 mm/3%, 3 mm/2%, 2 mm/3%, and 2 mm/2% increased by 2.2%, 2.2%, 4.4%, and 4.7% ( t=-2.76, -2.17, -4.72, -3.86, P<0.05), respectively. The increase in the calculation grid from 1.0 mm to 1.5 mm had greater effect on MapCHECK, with the γ passing rates at the criteria of 3 mm/3%, 3 mm/2%, 3 mm/1%, 2 mm/3% and 2 mm/2% decreased by 0.7%, 1.1%, 1.7%, 0.9%, 1.5% ( t=-6.15, -6.23, -5.98, -5.11, -8.34, P<0.05), respectively. The increases in the calculation grid from 1.0 mm to 2.0 mm had greater impact on ArcCHECK, with the γ passing rates at the criteria of 3 mm/3%, 3 mm/2%, 3 mm/1%, 2 mm/3%, 2 mm/2% decreased by 1.0%, 1.7%, 2.4%, 1.7%, 2.7% ( t=-4.75, -7.3, -8.63, -7.11, -8.26, P<0.05), respectively. The increase in the dose threshold from 5% to 10% had greater impact on ArcCHECK, with the γ passing rates at the criteria of 3 mm/3%, 3 mm/2%, 2 mm/3% and 2 mm/2% decreased by 1.1%, 1.4%, 2.5%, and 3.0% ( t=5.20, 5.68, 8.17, 9.99, P<0.05), respectively. Moreover, the increase in the dose threshold from 5% to 15% had more impact on 3DMap, with the γ passing rates at the criteria of 3 mm/3%, 3 mm/2%, 2 mm/3%, and 2 mm/2% decreased by 1.6%, 1.7%, 2.8%, and 3.2% ( t=3.25, 2.98, 4.40, 4.21, P<0.05), respectively. Conclusions:Target volume, calculation grid, and dose threshold are influencing factors in the dosimetric verification of three dosimetric verification systems for SBRT. Therefore, the effects of these parameters should be considered for different verification systems in clinical applications.
