Verification of doses to PTV and OAR and 2D dose distribution in IMRT for 8 accelerators in Jiangsu province
10.3760/cma.j.issn.0254-5098.2020.02.010
- VernacularTitle: 江苏省8台加速器调强放疗靶体积和危及器官剂量及二维剂量分布验证方法研究
- Author:
Chunyong YANG
1
;
Yuanyuan ZHOU
1
;
Xingjiang CAO
1
;
Xiang DU
1
;
Suming LUO
2
;
Xian XUE
2
;
Zhijian HE
2
;
Jin WANG
1
Author Information
1. Department of Radiation Protection, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing 210009, China
2. Key Laboratory of Radiological Protection and Nuclear Emergency, China CDC, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing 100088, China
- Publication Type:Journal Article
- Keywords:
Intensity modulated radiation therapy;
Radiochromic film;
Planned target volume;
Organ at risk;
Two-dimensional dose distribution
- From:
Chinese Journal of Radiological Medicine and Protection
2020;40(2):129-133
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To validate the method for measuring the TPV and OAR doses and 2D dose distribution in IMRT through using TLD and radiochromic film.
Methods:Eight medical linear accelerators (Valian, Elekta, Siemens) were selected. The polystyrene phantom provided by IAEA was CT scanned and the image obtained was transferred to TPS for formulation of treatment plan, prescription of PTV and OAR doses and calculation of corresponding monitoring unit (MU), IMRT was performed on the phantom using 6 MV X-ray. Irradiated TLDs and films were measured and evaluated at the Secondary Standard Dosimetry Laboratory at the Radiation Safety Institute of Chinese Center for Disease Control and Prevention.
Results:According to IAEA requirement, the relative deviations between TLD-measured and TPS-planned doses were within ±7.0% for the prescribed PTV and OAR doses. As measured result, the PTV values for 8 accelerators were in the range of 0.6% to 5.9%, consistent with the IAEA requirements, whereas the OAT values for 8 accelerators were within -0.6% to 7.0%, consistent the requirements. As IAEA required, the 2D dose distribution passing rate of 3 mm/3% should be higher than 90%. The film-measured and TPS-planned values for 8 accelerators were within 90.2% to 100.0%, consistent with the requirements.
Conclusions:TLD and radiochromic film are feasible in validating the PTV and OAR doses and the 2D dose distribution pass rate in IMRT. This method can be widely used in quality audit and internal verification in IMRT in medical institutiions on a large scale.
