A study on the suitability of HD-V2 film in ultra-high dose-rate electron beam dosimetry
10.3760/cma.j.cn113030-20220128-00042
- VernacularTitle:HD-V2胶片在超高剂量率电子线射束剂量测量中适用性的研究
- Author:
Ronghu MAO
1
;
Leijie MA
;
Hongchang LEI
;
Peng CHEN
;
Bing LI
;
Hui LUO
;
Han LIU
;
Xiuyan CHENG
;
Wei GUO
;
Hong GE
Author Information
1. 郑州大学附属肿瘤医院/河南省肿瘤医院放疗科，郑州 450003
- Keywords:
Ultra-high dose rate;
HD-V2 film;
Dose-rate dependence;
Energy dependence
- From:
Chinese Journal of Radiation Oncology
2023;32(4):333-338
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluate the usability of Gafchromic HD-V2 film for dose dosimetry in the ultra-high dose-rate (UD) electron beam from a modified medical linac, and to investigate the response between the energy and dose-rate dependence to the film.Methods:The HD-V2 film was utilized to measure the average dose-rate of the UD electron beam. The measured result was compared with those by advanced Markus chamber and alanine pellets. And characteristics of the UD electron beam were also measured by HD-V2 film. Energy dependence of HD-V2 film at three beam energies (6 MV X-ray, 9 MeV and 16 MeV electron beam) was investigated by obtaining and comparing the calibration curves based on the clinical linear accelerator in the dose range of 10-300 Gy. The dose-rate dependence of HD-V2 film was also studied by varying the dose rate among 0.03 Gy/s, 0.06 Gy/s and 0.1 Gy/s, and range of 100-200 Gy/s.Results:The measured average maximum dose-rate of 9 MeV UD electron beam at source skin distance (SSD) 100 cm was approximately 121 Gy/s using HD-V2 film, consistent with the results by advanced Markus chamber and alanine pellets. The measured percentage depth dose (PDD) curve parameters of the UD electron beam were similar to the conventional 9 MeV beam. The off-axis dose distribution of the UD electron beam showed the highest central axis, and the dose was gradually decreased with the increase of off-axis distance. The energy dependence of HD-V2 film had no dependency of 6 MV and 9, 16 MeV while measuring the dose in the range from 20 to 300 Gy. The HD-V2 film had no significant dose-rate dependency at the dose rate of 0.03 Gy/s, 0.06 Gy/s and 0.1 Gy/s for the clinical linear accelerator. Likewise, there was also no dose-rate dependence in the range 100-200 Gy/s in the modified machine.Conclusion:HD-V2 film is suitable for measuring ultra-high dose rate electron beam, independent of energy and dose rate.
