Effects of robust optimization parameters on radiation dose in proton radiotherapy for localized prostate cancer
10.3969/j.issn.1005-202X.2025.05.001
- VernacularTitle:鲁棒性优化参数对局限期前列腺癌质子放疗剂量的影响
- Author:
Hui ZHOU
1
;
Yibin ZHANG
1
;
Jiayi CHEN
1
;
Yujie WANG
1
;
Huan LI
1
;
Cheng XU
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 201801;医学影像先进技术研究院,上海 201800
- Publication Type:Journal Article
- Keywords:
prostate cancer;
proton therapy;
robust optimization;
setup error;
dosimetry
- From:
Chinese Journal of Medical Physics
2025;42(5):561-565,570
- CountryChina
- Language:Chinese
-
Abstract:
The effects of different robust optimization parameters on the doses to organs-at-risk(OAR)and the clinical target volume(CTV)in proton therapy plans for localized prostate cancer are explored for identifying the optimal robust optimization parameters.A retrospective analysis is conducted on 10 cases in which proton plans with a total dose of 76 Gy delivered in 38 fractions are designed.In robust optimization,uncertainties of 3.5%in range and setup errors of 3,5 and 7 mm are considered.After being grouped by setup errors,3 groups of plans are obtained.The effects of setup errors on the doses to CTV and OAR are analyzed,and the robustness of the CTV dose is assessed,including the worst-case values of dosimetric parameters and the passing rates under different scenarios.The results show that as the setup error increased,the doses to OAR tended to rise.Compared with the 3 mm plan group,the 5 mm and 7 mm plan groups experience increases of 1.99%and 5.15%in rectal V70,3.71%and 10.01%in rectal V45,0.93%and 2.55%in bladder V70,and 1.71%and 5.27%in bladder V45,respectively;similar patterns are observed for the doses to sigmoid colon and bulbous urethra,and the differences are statistically significant(P<0.05).In robustness analysis,the CTV D99 in the 5 mm and 7 mm plan groups increases by 0.68 Gy and 0.95 Gy as compared with the 3 mm plan group,with passing rates improving by 7.2%and 9.6%,respectively(passing criterion:D95 receives at least 100%of the prescribed dose),with significant differences(P<0.05).Considering both OAR dose and CTV robustness,the setup error of 5 mm is found to be a reasonable choice for robust optimization in proton therapy plans for localized prostate cancer,as it can effectively balance the enhancement of CTV dose robustness with the control of dose escalation to OAR.
