|Table of Contents|

Determining the optimal region of interest for AlignRT-guided positioning in postoperative radiotherapy for breast cancer(PDF)

《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]

Issue:
2023年第1期
Page:
1-6
Research Field:
医学放射物理
Publishing date:

Info

Title:
Determining the optimal region of interest for AlignRT-guided positioning in postoperative radiotherapy for breast cancer
Author(s):
LI Junyu YANG Jingxian YU Songmao LU Zihong ZHOU Shun CHEN Jixiang WANG Zhenfei DING Daqing WANG Meijiao DU Yi
Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing)/Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China
Keywords:
Keywords: breast cancer optical surface monitoring system region of interest positioning error
PACS:
R737.9;R811.1
DOI:
DOI:10.3969/j.issn.1005-202X.2023.01.001
Abstract:
Abstract: Objective To determine the optimal breast region of interest (ROI) among 3 typical suggested ROI for AlignRT-guided positioning in postoperative radiotherapy for breast cancer by comparing the positioning consistency between AlignRT errors and CBCT errors. Methods The clinical data of 33 cases of breast cancer patients undergoing AlignRT-guided positioning were analyzed retrospectively. After positioning, the AlignRT errors of 3 ROI, namely the whole chest region, the ipsilateral breast region, and the chest rigid region, were recorded for 197 CBCT. The registration results of CBCT and the positioning CT were fine-tuned based on the spines 6-dimensional registration target area, and the 6-dimensional CBCT errors were obtained. The absolute values of the differences between AlignRT errors and CBCT errors were used to quantify the positioning consistency. The AlignRT errors and positioning consistency in 3 different groups were compared. Results The proportion of deviations in linear directions (within 0.5 cm)/rotation directions (within 2.0°) of CBCT data in AlignRT-guided positioning was 99.92%. There were statistically significant differences in AlignRT errors in the Pitch (P<0.001) and Roll (P=0.002) directions among 3 ROI groups. The whole chest region as an optimal breast ROI in patient setup consistency shows a superiority than ipsilateral breast region and the chest rigid region in x (P=0.001), Rtn (P<0.001), Pitch (P=0.541) and Roll (P=0.001) directions. Conclusion The usage of AlignRT as a breast radiotherapy positioning guide tool to minimize the patient positioning errors in CBCT satisfied clinical requirements. The positioning consistency using the whole chest region (including bilateral breast/chest wall, sternum, ribs and clavicle) as the optimal ROI has proven its suitability than ipsilateral breast region and the chest rigid region. The whole chest region as the benchmark for scanning region in AlignRT system is the optimal ROI in postoperative radiotherapy for breast cancer.

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Last Update: 2023-01-07