Comparison of differences in dosimetry and treatment efficiency of modified radiotherapy plans after left-sided breast-conserving surgery
10.19745/j.1003-8868.2025066
- VernacularTitle:左侧乳腺癌保乳术后不同改良放疗计划的剂量学和治疗效率差异比较
- Author:
Jian-hai LIN
1
;
Jing FENG
1
;
Zhong-hua CHEN
1
;
Zhi-chao FU
1
;
Jie CHEN
1
;
Nan-bao ZHONG
1
Author Information
1. 联勤保障部队第九〇〇医院放射治疗科,福州 350025
- Publication Type:Journal Article
- Keywords:
left-sided breast-conserving surgery;
modified radiotherapy;
treatment efficiency;
dosimetry;
intensity-mo-dulated radiation therapy;
volume-modulated arc therapy
- From:
Chinese Medical Equipment Journal
2025;46(4):45-51
- CountryChina
- Language:Chinese
-
Abstract:
Objective To compare the differences in dosimetry and treatment efficiency of three radiotherapy plans after left-sided breast-conserving surgery,including modified intensity-modulated radiation therapy(IMRT),cross-field volume-modulated arc therapy(VMAT)or improved VMAT,so as to provide references for clinical practice.Methods Three radiotherapy plans of modified IMRT,cross-field VMAT and improved VMAT were designed for 12 patients after left-sided-breast-conserving surgery.The modified IMRT with five irradiation fields and the improved VMAT with two arcs were modified by not setting cross-fields while determining the start and end angles with the rays passing through the least lung area.The cross-field VMAT had its start and end angles set based on the cross-fields.The doses to the target areas,peripheral organs at risk,heart and its substructures were evaluated,and dose verification was carried out.The three plans were compared in terms of treatment efficiency and gamma pass rate.SPSS 22.0 was used for statistical analysis.Results All the three plans behaved well in dose distribution.In terms of planning gross tumor volume dosimetry dosimetry,the improved VMAT and modified IMRT gained advantages than others in CI and D50,respectively,with the differences being significant(all P<0.05).In terms of planning target volume dosimetry,the modified IMRT had the V107 and D50 lower than those of the others,with the differences being significant(P<0.05).In terms of the protection of peripheral organs at risk,V5 of the left lung,Dmean of the right lung and Dmean of the healthy breast were lower in the modified IMRT plan than in the other 2 plans,with statistically significant differences(P<0.05);V20,V30,V35 and V40 of the left lung were lower in the modified VMAT plan than in the other 2 plans,with statistically significant differences(P<0.05).In terms of protection of heart and its substructures,the left ventricle V20,V30 and Dmean of the improved VMAT plan behaved better than those of other 2 plans,and the difference was statistically significant(all P<0.05).In terms of treatment efficiency,the cross-field VMAT plan had the lowest MU while highest treatment efficiency;the improved VMAT plan had the MU higher while the treatment efficiency lower than the cross-field VMAT plan;the modified IMRT plan had the highest MU while the lowest gamma pass rate,and the differences in the MUs and gamma pass rates among the three plans were statistically significant(P<0.05).Conclusion Under the same standard conditions,the cross-field VMAT and improved VMAT plans show technical advantages.Though the improved VMAT plan has the treatment efficiency lower than the cross-field VMAT,it decreases the possibility of radiocardiac injury in terms of dosimetry and thus can be used for radiotherapy after left-sided breast-conserving surgery.[Chinese Medical Equipment Journal,2025,46(4):45-51]
