Abstract：Objective To analyze the influence of MLC leaf position calibration on the chest IMRT verification. Methods The
3D Dosimetric verification system of Delta4 was used to measure the IMRT plan of chest tumor patients before and after MLC
calibration, and to analyze the differences of Dose deviation (DD), Distance to Agreement (DTA) and Gamma pass rate. Results
When the three evaluation indexes of DD, DTA and gamma pass rate were applied, the pass rates of the IMRT plan of 9 chest patients
after MLC calibration were all improved. The average pass rate of 2% DD, 2 mm DTA, 2%/2 mm Gamma after MLC calibration
increased by 19.29%, 22.86%, 19.53%, respectively. When the evaluation indexes were 4% DD, 4 mm DTA, and 4%/4 mm Gamma,
the increase in the average pass rate was moderate, with 17.27%, 3.48%, and 2.86%, respectively. Thus, the evaluation indicators 4%
DD, 4 mm DTA, and 4%/4 mm Gamma were less sensitive to the position errors of MLC. Conclusion The pass rate of dose
verification was directly affected by the precision of MLC leaf position in IMRT, if it decreased, the position precision of MLC leaf
should be considered.
张惠玲，许会军，吴小良，李静，陈晓芳，赵鹏，刘朝兴，李鹏. 多叶准直器叶片位置校准对胸部肿瘤IMRT计划验证的影响[J]. 中国医疗设备, 2019, 34(8): 81-84.
ZHANG Huiling, XU Huijun, WU Xiaoliang, LI Jing, CHEN Xiaofang, ZHAO peng, LIU Chaoxing, LI Peng. Impact of MLC Leaf Position Calibration on the Chest IMRT Verification. China Medical Devices, 2019, 34(8): 81-84.
