Comparison of absolute dose calibration for linear accelerator in FFF mode based on IAEA 277 report versus IAEA 398 report(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2020年第7期
- Page:
- 838-842
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Comparison of absolute dose calibration for linear accelerator in FFF mode based on IAEA 277 report versus IAEA 398 report
- Author(s):
- JIA Yajun; SHEN Wentong; YAN Yuanlin; CHEN Jiayi; HE Xiaodong
- Department of Radiotherapy, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
- Keywords:
- Keywords: absolute dose calibration IAEA 277 report IAEA 398 report flattening filter free mode linear accelerator
- PACS:
- R811.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2020.07.008
- Abstract:
- Abstract: Objective To compare the results of absolute dose calibration for linear accelerator in flattening filter free (FFF) mode based on International Atomic Energy Agency (IAEA) 277 report versus IAEA 398 report. Methods According to IAEA 398 report, the radiation quality and percentage depth dose of 6X-FFF and 10X-FFF beams were measured on the newly installed Varian Edge accelerator in Ruijin Hospital, Shanghai Jiaotong University School of Medicine. Ionization chamber correction factor kQ, polarity effect correction factor kpol and recombination correction factor ks were calculated and then the calibration results were compared with those obtained based on IAEA 277 report which is currently adopted in China. Results For 6X-FFF and 10X-FFF beams, the radiation quality was 0.629 and 0.708, respectively. The calibration depth for both 6X-FFF and 10X-FFF beams was 10 cm. The kQ, kpol, and ks for 6X-FFF beams were 0.997, 1.000 9, 1.005 0, respectively, while those for 10X-FFF beams were 0.988, 1.001 2 and 1.006 9, respectively. Compared with those in FF mode, the recombination effects for 6X-FFF and 10X-FFF beams in FFF modes were higher by 0.36% and 0.32%, respectively. The differences in the absolute dose calibration of 6X-FFF and 10X-FFF beams between IAEA 398 report and IAEA 277 report were -1.0% and 0.7%, respectively. Conclusion In FFF mode, the difference in the absolute dose calibration based on IAEA 398 report versus IAEA 277 report is less than 2%. Furthermore, the procedure in IAEA 398 report is more convenient in clinical practice.
Last Update: 2020-07-28