Evaluation of fixed‐jaw IMRT and tangential partial‐VMAT radiotherapy plans for synchronous bilateral breast cancer irradiation based on a dosimetric study

作者：Jianghua Huang, Xiuxiu Wu, Xiao Lin, Juntian Shi, Yujia Ma, Song Duan, Xiaobo Huang · 发表于：Journal of Applied Clinical Medical Physics · 年份：2019 · DOI：10.1002/acm2.12688 · 被引用次数：28 · 研究领域：Breast Cancer Treatment Studies、Advanced Radiotherapy Techniques、Radiation Therapy and Dosimetry

Abstract Purpose To investigate the fixed‐jaw intensity‐modulated radiotherapy (F‐IMRT) and tangential partial volumetric modulated arc therapy (tP‐VMAT) treatment plans for synchronous bilateral breast cancer (SBBC). Materials and method Twelve SBBC patients with pTis‐2N0M0 stages who underwent whole‐breast irradiation after breast‐conserving surgery were planned with F‐IMRT and tP‐VMAT techniques prescribing 42.56 Gy (2.66 Gy*16f) to the breast. The F‐IMRT used 8‐12 jaw‐fixed tangential fields with single (sF‐IMRT) or two (F‐IMRT) isocenters located under the sternum or in the center of the left and right planning target volumes (PTVs), and tP‐VMAT used 4 tangential partial arcs with two isocenters located in the center of the left and right PTVs. Plan evaluation was based on dose‐volume histogram (DVH) analysis. Dosimetric parameters were calculated to evaluate plan quality; total monitor units (MUs), and the gamma analysis for patient‐specific quality assurance (QA) were also evaluated. Results For PTVs, the three plans had similar D mean and conformity index (CI) values. F‐IMRT showed a slightly better target coverage according to the V 100% values and demonstrated an obvious reduction in V 105% and D max compared with the values observed for sF‐IMRT and tP‐VMAT. Compared with tP‐VMAT, sF‐IMRT was slightly better in terms of V 100% , V 105% and D max . In addition, F‐IMRT achieved the best homogeneity index (HI) values for PTVs. Concerning healthy tissue, tP‐VMAT had an ...