title: Dosimetric comparison of intensity modulated and volumetric arc radiation therapy for gastric cancer.
abstract: The aim of the present study was to compare radiotherapy treatment plans for gastric cancer using intensity-modulated radiotherapy (IMRT) and single/double-arc volumetric modulated arc therapy (SA/DA-VMAT) delivery techniques. A total of 29 postoperative gastric cancer patients were enrolled in this study and each patient was scheduled 5-field IMRT (5F-IMRT), 7-field IMRT (7F-IMRT), SA-VMAT and DA-VMAT techniques. Dose-volume histogram statistics, conformal index (CI), homogeneity index (HI) and monitor units (MUs) were analyzed to compare treatment plans. The DA-VMAT plans exceeded the other three methods in terms of planning tumor volume dose and organs at risk in the kidneys, but not in the liver. DA-VMAT exhibited a better mean CI (0.87±0.03) and HI (0.10±0.01) than the other techniques. In addition, for the kidneys the dose sparing (V13, V18 and mean kidney dose) was improved by DA-VMAT plans. Similar results were observed for MUs. However, 5F-IMRT showed a marginal advantage in V30 and mean dose in normal liver when compared with DA-VMAT. The results of this study suggest that DA-VMAT provides improved tumor coverage when compared with 5F-IMRT, 7F-IMRT and SA-VMAT; however, DA-VMAT exhibits no advantage in liver protection when compared with 5F-IMRT. Further studies are required to establish differences in treatment outcomes among the four technologies.
authors.affiliation: Department of Abdominal Oncology, Cancer Center of West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Abdominal Oncology, Cancer Center of West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
authors.forename: Jianshuang
authors.initials: J
authors.lastname: Zeng
authors.affiliation: Department of Abdominal Oncology, Cancer Center of West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
authors.forename: Zi
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Abdominal Oncology, Cancer Center of West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Department of Abdominal Oncology, Cancer Center of West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China ; State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
authors.forename: Yuquan
authors.initials: Y
authors.lastname: Wei
keywords: dosimetric comparison; gastric cancer; intensity-modulated radiotherapy; volumetric modulated arc therapy