Dosimetric effects of isocenter on intensity-modulated radiotherapy for MR-Linac
10.3760/cma.j.cn112271-20220126-00035
- VernacularTitle:磁共振加速器放疗计划中心点位置对剂量学的影响
- Author:
Shouliang DING
1
;
Hongdong LIU
;
Yongbao LI
;
Bin WANG
;
Xiaoyan HUANG
Author Information
1. 中山大学肿瘤防治中心放疗科，华南肿瘤学国家重点实验室，肿瘤医学协同创新中心 510060
- Keywords:
MR-Linac;
Plan isocenter;
Plan evaluation;
Treatment plan design
- From:
Chinese Journal of Radiological Medicine and Protection
2022;42(6):433-437
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the dosimetric effects on off-center tumour treatment plan resulting from the MR-Linac-based isocenter position radiotherapy plan.Methods:The cases of 19 patients who were treated in Sun Yat-sen University Cancer Center in 2020 were collected in this study. Two different IMRT plans were designed for each patient with off-center tumor both for group A with planned isocenter position as IMRT and group B with planed target center position as geometric center. The conformity index and homogeneity index of target, the dose normal tissue and the number of MU were compared between two plans.Results:The two IMRT plans met clinical dosimetric requirements. No statistical differences were found both in homogeneity index and conformity index ( P>0.05). Also there was no differences found in doses to normal tissues. However, the MU number (1 149±903, t=2.804, P=0.012) in group A was higher than that in group B (970±652). Conclusions:It is feasible to perform MR-Linac-based off-center treatment plan.
