Optical surface monitoring-based real-time 3D in vivo dose verification for patients with left breast cancer undergoing deep inspiration breath-hold radiotherapy
10.3760/cma.j.cn112271-20240109-00011
- VernacularTitle:基于光学体表监测的左侧乳腺癌深吸气屏气放疗实时三维在体剂量验证分析
- Author:
Jiahao WANG
1
;
Hongling XIE
;
Yadong ZHAO
;
Pengfei ZHOU
;
Hui LI
;
Qiu TANG
Author Information
1. 浙江大学医学院附属妇产科医院放疗科，杭州 310000
- Keywords:
Left breast cancer;
Deep inspiration breath-hold surface guided radiation therapy;
3D in vivo dose verification;
γ pass rate
- From:
Chinese Journal of Radiological Medicine and Protection
2024;44(6):517-522
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To perform optical surface monitoring-based three-dimensional (3D) in vivo dose verification for patients with left breast cancer undergoing deep inspiration breath-hold surface-guided radiation therapy (DIBH-SGRT) and to investigate the dosimetric differences in the target volumes and related factors affecting γ pass rates. Methods:Totally 20 patients with left breast cancer who received DIBH-SGRT at the Department of Radiation Oncology, Women′s Hospital, School of Medicine, Zhejiang University were selected. The optical surface monitoring-based intrafractional displacement deviations of the patients during DIBH were recorded. Meanwhile, electronic portal imaging device (EPID)-based in vivo dosimetry (EIVD) verification was performed for patients during the DIBH-SGRT, and γ pass rates were measured with the criteria of 2 mm/2%, 3 mm/3%, and 3 mm/5%. The dosimetric differences between planning target volumes (PTVs) and organs at risk (OARs) were analyzed based on dose-volume histograms (DVHs). Furthermore, Pearson correlation analysis was employed to determine the correlation of three γ pass rates with dosimetric differences and displacement deviations. Results:The average pass rates with the criteria of 2 mm/2%, 3 mm/3%, and 3 mm/5% were determined at 73.43%, 86.00%, and 92.96%, respectively, and the average deviations between EIVD measured doses and planned doses in PTV_TB and PTV Dmean were proved to be 0.23% and 0.59%, respectively ( P > 0.05). Pearson analysis revealed that the γ pass rates exhibited a weak correlation with dosimetric differences in PTVs( R<0.7) but strong correlations with intrafractional displacement deviations in Lat and Vert directions during DIBH ( R > 0.7). Conclusions:EIVD verification can ensure the high accuracy of dose delivery in PTVs during DIBH-SGRT for left breast cancer. Additionally, the EIVD verification system has the potential to detect displacement deviations during breath holding.
