Clinical dosimetry commissioning of 1.5 T MR-linac
10.3760/cma.j.cn113030-20210906-00351
- VernacularTitle:1.5 T MR加速器临床剂量调试
- Author:
Minghui LI
1
;
Yuan TIAN
;
Ke ZHANG
;
Chuanmeng NIU
;
Hongkai WANG
;
Kuo MEN
;
Jianrong DAI
Author Information
1. 国家癌症中心/国家肿瘤临床医学研究中心/中国医学科学院北京协和医学院肿瘤医院放疗科，北京 100021
- Keywords:
Magnetic resonance accelerator;
Dosimetry commissioning;
Model
- From:
Chinese Journal of Radiation Oncology
2022;31(1):29-34
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To introduce the clinical dosimetry commissioning methods and results of the 1.5 T MR-linac.Methods:In May, 2019, an Elekta Unity 1.5 T MR-linac was installed in Cancer Hospital, Chinese Academy of Medical Sciences and dosimetry commissioning was performed with magnetic field compatible measuring instruments. Commissioning items include absolute dose calibration, data acquisition and planning system model verification.Results:Absolute dose calibration in magnetic field should be corrected by magnetic field correction factor. The standard output dose of Unity was 87 cGy. Gamma analysis (3%/2 mm) was performed on the beam collection data and the planning system calculation data. The average pass rate of dose verification of standard field test cases was 96.41%, and the TG119 test case was 98.24%. The IROC end to end test case was 97.5%(7%/4 mm).Conclusions:The planning system model and the beam collection data have good consistency. The dose verification results of the standard field and TG119 test cases meet the general tolerance limit requirements of the AAPM TG218 report, and the verification results of the IROC end-to-end test cases meet the IROC center standards.
