Preliminary study of tolerance limits and action limits of IMRT plan dose verification based on AAPM-TG218 report
10.3760/cma.j.cn113030-20200330-00146
- VernacularTitle:基于AAPM-TG218报告对调强放疗计划剂量验证容差和干预限值的初步研究
- Author:
Wei GUO
1
;
Ronghu MAO
;
Bing LI
;
Dandan GENG
;
Xiuyan CHENG
;
Hongchang LEI
Author Information
1. 河南省肿瘤医院/郑州大学附属肿瘤医院放疗科 450008
- Keywords:
AAPM-TG218;
Dose verification;
γ passing rate;
Tolerance limit;
Action limit
- From:
Chinese Journal of Radiation Oncology
2021;30(8):817-821
- CountryChina
- Language:Chinese
-
Abstract:
Objective:Based on the AAPM-TG218 report, the dose verification of intensity-modulated radiotherapy (IMRT) plans were classified to understand the current status, establish the process and determine the limits of dose verification in our hospital.Methods:Different combinations of tumor locations, accelerators, treatment planning systems and verification devices in our hospital were verified and compared to determine the tolerance limits and action limits of each combination. The measurement requirement was adopted according to the AAPM-TG218 report, and 80 cases were selected for each measurement. The measurement procedures were implemented based upon the AAPM-TG218 report and clinical experience of our hospital.Results:The clinical action limits of IMRT plans in our hospital could meet the recommended range of the AAPM-TG218 report, and the tolerance limits were slightly lower than the AAPM-TG218 report′s recommendation (93.94% for 3%/2 mm). The measurement of verification devices was related to the sensitivity. The tolerance limits measured by EPID were higher than ArcCHECK, especially when the dose/distance requirements were more stringent (94.12% and 92.03% for 3%/2 mm, P=0.074; 86.82% and 74.61% for 2%/2 mm, P=0.017). Conclusion:Through the AAPM-TG218 report, the work flow of IMRT dose verification and the limit range are established in our hospital, providing guidance for subsequent clinical dosimetric measurement.
