Abstract

Info

Author(s):: HU Xinggang; XIONG Dun; YANG Bo; ZHAO Xinhua; CHEN Meng; YE Zhimao; Pu’er People’s Hospital, Pu’er 665000, China

Abstract:: Abstract: Objective To calculate Gamma passing rates based on radiation fields for evaluating the accuracy of treatment delivery. Methods Six intensity-modulated radiotherapy (IMRT) verification plans were randomly selected from Oncentra Masterplan treatment planning system. The verification plans in DICOM formats were exported, and Matlab software was used to reconstruct multi-leaf collimator regions and doses. Then the validation plans were ported to MatriXX phantom for dose distribution measurement. Finally, Matlab code was used to analyze the calculated dose distribution of verification plans and the absolute dose distribution measured with MatriXX phantom. Results The Gamma passing rate obtained by traditional calculation method was greatly affected by the selection of calculation regions, but the effect was avoided by the proposed method which takes the radiation fields as calculation regions. There were significant differences in the Gamma passing rates obtained by traditional and proposed methods (P<0.05). Conclusion Dose verification based on radiation fields avoids the effect of [Dn] values on Gamma passing rate. Moreover, dose-area histogram is used to analyze the dosimetric characteristics in radiation fields, which is helpful for evaluating the accuracy of clinical treatment and guiding clinical work.