Dose reconstruction of electronic portal imaging device based on calibration and calculation
10.3969/j.issn.1005-202X.2024.01.008
- VernacularTitle:基于标定和计算的电子射野影像系统剂量重建
- Author:
Jianfeng SUI
1
,
2
,
3
;
Jiawei SUN
;
Kai XIE
;
Liugang GAO
;
Tao LIN
;
Xinye NI
Author Information
1. 南京医科大学附属常州第二人民医院放疗科,江苏常州 213161
2. 南京医科大学医学物理研究中心,江苏常州 213161
3. 江苏省医学物理工程研究中心,江苏常州 213161
- Keywords:
dose calibration;
dose calculation;
electrionic portal imaging device;
reconstruction;
verification
- From:
Chinese Journal of Medical Physics
2024;41(1):54-59
- CountryChina
- Language:Chinese
-
Abstract:
A dose reconstruction algorithm for electrionic portal imaging device(EPID)based on calibration and calculation is developed.The raw data of EPID in continuous acquisition mode are corrected for dark field and gain,and the gray level features of bright field are used to determine the field boundary.Subsequently,MU calibration,off-axis calibration and field size calibration are performed on the EPID data,and dose reconstruction is carried out based on the calibrated superimposed flux and the Monte Carlo model of the linac head.Nine cases of IMRT plans are selected for verification and measurement using EPID and MapCheck separately,and the passing rates between the two tools are compared under different gamma criteria(3%/3 mm and 2%/2 mm).For a planned case,the average passing rates of multiple cases verified by MapCheck under the two criteria were 99.02%±1.28%and 90.84%±4.49%,and the average passing rates of the EPID reconstruction models were 98.86%±1.19%and 91.39%±4.80%.Compared with MapCheck,the EPID reconstruction algorithm based on calibration and calculation has no significant difference in the passing rate of IMRT plan verification(P＞0.05),which meets the clinical requirements of dose verification.
