Study of dosimetric comparison of auto plan and fall back plan of radiotherapy after breast conserving surgery for breast cancer based on Ethos adaptive radiotherapy system
10.3969/j.issn.1672-8270.2025.03.003
- VernacularTitle:基于Ethos自适应放射治疗系统的乳腺癌保乳术后放射治疗自动计划与导入计划的剂量学对比研究
- Author:
Chao LI
1
;
Lu CAO
1
;
Weixiang QI
1
;
Longyan DUAN
1
Author Information
1. 上海交通大学医学院附属瑞金医院放射治疗科 上海 200025;上海市质子治疗转化研究重点实验室 上海 200025
- Publication Type:Journal Article
- Keywords:
Breast cancer;
Ethos;
Auto Plan;
Fall back Plan;
Dosimetry
- From:
China Medical Equipment
2025;22(3):10-16
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To compare and research dosimetric differences between auto plan and fall back plan in Ethos adaptive radiotherapy system in radiotherapy after breast conserving surgery for breast cancer,and explore the clinical value of two techniques under the Ethos platform in the radiotherapy after breast conserving surgery.Methods:The data of a total of 15 patients with breast cancer,who received radiotherapy after breast conserving surgery for breast cancer at Ruijin Hospital,Shanghai Jiao Tong University School of Medicine in 2022,were selected.Based on the Ethos planning system,the auto plans of the average score of 7 fields(7F_IMRT),9 field(9F_IMRT)and 12 field(12F_IMRT),as well as a fall back plan of 12 fields,were designed respectively for each patient.The dosimetric differences of conformity index(CI)and homogeneity index(HI)of dose distribution of target region,and the dose of organs at risk(OAR)were compared and evaluated.Results:The fall back plan can improve dose distribution of target region,and the average HI value of the dose of target region of 15 patients was 0.020±0.005,which was superior to those[7F_IMRT(0.065±0.015),9F_IMRT(0.024±0.004)and 12F_IMRT(0.024±0.0045)]of 3 kinds of auto plans,and the differences of them between two kinds of plans were significant(F=12.687,3.638,4.885,P<0.05).In 8 patients with breast cancer at left side,the mean dose(Dmean),volume percentages in receiving 5,10,20,30 Gy doses(V5Gy,V10Gy,V20Gy,V30Gy)in the affected side of lung in fall back plan were better than those in auto plan,and the differences of them between two kinds of plans were significant(F=24.31,64.59,18.02,7.32,5.74,P<0.05).The average Dmean of receiving dose of heart,V5Gy,V10Gy and V30Gy of fall back plan were respectively(244.83±53.93)cGy,(9.64±2.94)%,(4.28±2.0)%and(0.51±0.5)%,which were better than those of three kinds of auto plans,and the differences of them between two kinds of plans were significant(F=10.17,12.05,4.59,3.95,P<0.05).The Dmean and V5Gy of the health side of lung,and Dmean of health side of breast in fall back plan were better than those in three kinds of auto plans,and the differences of them between two kinds of plans were significant(F=27.99,6.26,35.89,P<0.05).In 7 patients with breast cancer at right side,the Dmean,V5Gy,V10Gy,V20Gy and V30Gy of affected side of lung in fall back plan were better than those of three kinds of auto plans,and the differences of them between two kinds of plans were significant(F=3.43,3.85,2.32,2.36,3.59,P<0.05).The Dmax,Dmean and V5Gy of heart in fall back plan were all better than those of three kinds of auto plans,and the differences of them between two kinds of plans were significant(F=10,10.22,3.96,P<0.05).The Dmean and V5Gy of health side of lung,and the Dmean of health side of breast in fall back plan were better than those in three kinds of auto plans,and the differences of them between two plans were significant(F=20.87,4.17,59.83,P<0.05).Conclusion:Compared with auto plan of Ethos system of 7F_IMRT,9F_IMRT and 12F_IMRTB,the homogeneity of target region of the Fall Back plan is better,and the doses of lung and heart of affected side of that are lower,and the doses of other OAR all were within the requirement of clinical limitation.Fall back plan has higher clinical application value in radiotherapy after breast conserving surgery for breast cancer.
