PMID- 31483573 OWN - NLM STAT- MEDLINE DCOM- 20200226 LR - 20231014 IS - 1526-9914 (Electronic) IS - 1526-9914 (Linking) VI - 20 IP - 9 DP - 2019 Sep TI - Evaluation of fixed-jaw IMRT and tangential partial-VMAT radiotherapy plans for synchronous bilateral breast cancer irradiation based on a dosimetric study. PG - 31-41 LID - 10.1002/acm2.12688 [doi] AB - 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 advantage in minimizing the high dose volume. The MUs of the tP-VMAT plan were decreased approximately 1.45 and 1 times compared with the sF-IMRT and F-IMRT plans, respectively, and all plans passed QA. For the lungs, heart and liver, F-IMRT achieved the smallest values in terms of D(mean) and showed a significant difference compared with tP-VMAT. Simultaneously, sF-IMRT was also superior to tP-VMAT. For the coronary artery, tP-VMAT achieved the lowest D(mean) , while the value for F-IMRT was 2.24% lower compared with sF-IMRT. For all organs at risk (OARs), tP-VMAT was superior at the high dose level. In contrast, sF-IMRT and F-IMRT were obviously superior at the low dose level. The sF-IMRT and F-IMRT plans showed consistent trends. CONCLUSION: All treatment plans for the provided techniques were of high quality and feasible for SBBC patients. However, we recommend F-IMRT with a single isocenter as a priority technique because of the tremendous advantage of local hot spot control in PTVs and the reduced dose to OARs at low dose levels. When the irradiated dose to the lungs and heart exceed the clinical restriction, two isocenter F-IMRT can be used to maximize OAR sparing. Additionally, tP-VMAT can be adopted for improving cold spots in PTVs or high-dose exposure to normal tissue when the interval between PTVs is narrow. CI - (c) 2019 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine. FAU - Huang, Jiang-Hua AU - Huang JH AD - Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. AD - Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. FAU - Wu, Xiu-Xiu AU - Wu XX AD - Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. AD - Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. FAU - Lin, Xiao AU - Lin X AD - Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. AD - Department of Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. FAU - Shi, Jun-Tian AU - Shi JT AD - Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. AD - Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. FAU - Ma, Yu-Jia AU - Ma YJ AD - Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. AD - Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. FAU - Duan, Song AU - Duan S AD - Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. AD - Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. FAU - Huang, Xiao-Bo AU - Huang XB AD - Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. AD - Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. AD - Department of Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. LA - eng PT - Evaluation Study PT - Journal Article DEP - 20190904 PL - United States TA - J Appl Clin Med Phys JT - Journal of applied clinical medical physics JID - 101089176 SB - IM MH - Adult MH - *Algorithms MH - Breast Neoplasms/*radiotherapy MH - Computer Simulation MH - Female MH - Humans MH - Middle Aged MH - Organs at Risk/*radiation effects MH - Prognosis MH - Radiotherapy Dosage MH - Radiotherapy Planning, Computer-Assisted/*methods MH - Radiotherapy, Intensity-Modulated/*methods PMC - PMC6753728 OTO - NOTNLM OT - dosimetric comparison OT - fixed-jaw intensity-modulated radiotherapy (F-IMRT) OT - synchronous bilateral breast cancer (SBBC) OT - tangential partial volumetric modulated arc therapy (tP-VMAT) COIS- The authors have no relevant conflict of interest to disclose. EDAT- 2019/09/05 06:00 MHDA- 2020/02/27 06:00 PMCR- 2019/09/04 CRDT- 2019/09/05 06:00 PHST- 2018/12/18 00:00 [received] PHST- 2019/07/03 00:00 [revised] PHST- 2019/07/10 00:00 [accepted] PHST- 2019/09/05 06:00 [pubmed] PHST- 2020/02/27 06:00 [medline] PHST- 2019/09/05 06:00 [entrez] PHST- 2019/09/04 00:00 [pmc-release] AID - ACM212688 [pii] AID - 10.1002/acm2.12688 [doi] PST - ppublish SO - J Appl Clin Med Phys. 2019 Sep;20(9):31-41. doi: 10.1002/acm2.12688. Epub 2019 Sep 4.