Dosimetric effect of combined physical optimization and gEUD optimization on hippocampus avoidance whole-brain radiotherapy
10.19745/j.1003-8868.2025199
- VernacularTitle:物理优化联合gEUD优化对海马保护性全脑放疗的剂量学影响研究
- Author:
Zhen LI
1
;
Jin-bao JIAO
;
Ding-biao GU
;
Meng-hao CHEN
Author Information
1. 中山市人民医院放疗科,广东 中山 528400
- Publication Type:Journal Article
- Keywords:
hippocampus avoidance whole-brain radiotherapy;
generalized equivalent uniform dose;
intensity-modulated radiation therapy;
physical optimization;
biological optimization
- From:
Chinese Medical Equipment Journal
2025;46(11):44-49
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the dosimetric effect of a biological optimization approach combining physical optimization with generalized equivalent uniform dose(gEUD)on hippocampus avoidance whole-brain radiotherapy(HA-WBRT).Methods A retrospective review was conducted of 20 patients with multiple brain metastases who underwent whole-brain radiotherapy at a certain hospital between May 2021 and December 2022.Two radiotherapy plans including plan_DV and plan_gEUD were designed for each patient by using Eclipse V15.6 planning system.Plan_DB used conven-tional dose-volume(DV)physical optimization,and plan_gEUD went through re-optimization with an Upper gEUD function applied to hippocampal region and hippocampal protection zone.Evaluation was carried out in accordance with RTOG 0933 guidance for the absolute values D2%,D98%and D50%received by 2%,98%,and 50%of the target volume in the planning target volume,conformity index(CI),homogeneity index(HI),gradient index(GI)and the dosimetric indexes of hippocampal region,hippocampal protection zone and other organs at risk(OARs).SPSS 26.0 software was used for statistical analysis.Results The two kinds of plans both had the target volume coverage meet the requirements of RTOG 0933 guidance.Plan_gEUD had the D98%,D2%and V105 of the planning target volume lower than those of plan_DV,with the differences being statistically significant(all P<0.05).The two kinds of plans had no significant differences in monitor unit,D50%and Dmax of PTV,HI,CI and GI(all P>0.05).Plan_gEUD had the Dmax and Dmean of hippocampal region and them of hippocampal pro-tection zone lower than those of plan_DV,and the optic nerve Dmax of plan_gEUD was higher than that of plan_DV,with the differences being statistically significant(all P<0.05).There were no statistically significant differences between the two kinds of plans in the Dmax of inner ear,optic chiasm,lens,and eyeball(all P>0.05).Conclusion Physical optimization in the HA-WBRT plan combined with gEUD optimization results in a greater dose reduction to the hippocampus while maintaining target coverage.
