A method of measuring the field output factor based on daisy-chaining
10.3760/cma.j.issn.1004-4221.2018.12.012
- VernacularTitle:基于菊花链射野输出因子测量方法
- Author:
Minghui LI
1
;
Pan MA
;
Yuan TIAN
;
Junjie MIAO
;
Kuo MEN
;
Ke ZHANG
;
Chuanmeng NIU
;
Jianrong DAI
Author Information
1. 国家癌症中心/中国医学科学院北京协和医学院肿瘤医院放疗科
- Keywords:
Daisy-Chaining;
Output factor;
Measurement method
- From:
Chinese Journal of Radiation Oncology
2018;27(12):1088-1092
- CountryChina
- Language:Chinese
-
Abstract:
Objective improve the accuracy of the measurement results by using the field output factor measurement method based on daisy-chaining.Methods The Varian Edge Accelerator 6 MV X-ray data were measured using the IBA CC13 ionization chamber, IBA CC01 ionization chamber, IBA Razor semiconductor detector , IBA EFD semiconductor detector and Gafchromic EBT 3 film , respectively. Results Compared with the daisy-chaining measurement method,the results obtained by the conventional measurement method using CC13 were smaller. The deviation value was 16. 71% in the 1 cm × 1 cm field. The measurement results in a larger field via CC01 were bigger with a deviation of 8. 39% in the 40 cm × 40 cm filed. The measurement results via Razor in a larger field were larger with a deviation of 9. 40% in the 40 cm × 40 cm field. The measurement results were similar between EFD and Razor with a deviation of 9. 14% in the 40 cm × 40 cm field. The results of the film measurement were equivalent to those obtained from the daisy-chaining method in a field of＞ 1 cm × 1 cm with a deviation within 1. 60%,whereas the deviation was increased to 3. 13% in the 1 cm× 1 cm field. The results were consistent with daisy-chaining measurement if the 3 cm × 3 cm or 4 cm × 4 cm fields were selected as the intermediate fields with the maximum deviation of 0. 29%. Conclusions For the detectors with changing response along with the field size,daisy-chaining measurement method can be utilized to extend the measurement range and improve the accuracy of the measurement results.
