摘要
Abstract
Objective:To compare dosimetric differences among three kinds of techniques including intensity modulated radiotherapy(IMRT)and volumetric modulated arc therapy(VMAT)of adopting photon,and intensity modulated proton therapy(IMPT)in radiotherapy for thymic tumors,with a particular focus on assessing the radiation doses to the heart and substructures of that,so as to provide precise reference in selecting clinically individual plan.Methods:Imaging data from 35 patients with thymic tumors who received radiotherapy at the Department of Radiotherapy of Weifang NO.2 People's Hospital between January 2017 and October 2023 were retrospectively collected.Based on the positioned computed tomography(CT)image of each patient,the plans of three kinds of radiotherapy methods including IMRT,VMAT and IMPT were respectively designed.The conformity index(CI),homogeneity index(HI)and gradient index(GI)at target area,and mean dose(Dmean),maximum dose(Dmax),and dose volume parameters(V5-V50)of the planning target volume(PTV)and organs at risk(OARs)were compared among three kinds of plans.Results:All of three kinds of plans can meet clinical requirements for dose of target area.The IMRT and VMAT plans showed slight advantages in terms of CI and HI of target area.For the heart,the Dmean(3.82±2.99 Gy)of the IMPT plan group was significantly lower than(8.80±5.84 Gy)of the IMRT plan group,and(8.85±6.40 Gy)of VMAT plan group,with a statistically significant difference(H=24.49,P<0.05).For the substructures of cardiac tissue,the Dmean of the left atrium of the IMPT plan group was significantly lower than that of the IMRT plan and VMAT plan groups,and the difference was significant(H=54.68,P<0.05).The Dmean of the left anterior descending branch of the IMPT group was also lower than those of the IMRT plan and VMAT plan groups(H=7.75,P<0.05).Conclusion:The IMPT plan demonstrates superior dosimetric advantages in protecting normal tissues(NT),especially the heart and the critical substructures of heart,which can provide better protection for the heart and the substructures of that.关键词
胸腺肿瘤/质子治疗/剂量学比较/心脏亚结构Key words
Thymic tumor/Proton therapy/Dosimetric comparison/Cardiac substructure分类
医药卫生
