Application of three-dimensional arterial spin labeling MR imaging to quantify changes in hippocampal perfusion before and after radiotherapy for brain metastases
10.3969/j.issn.1005-202X.2025.02.002
- VernacularTitle:磁共振三维动脉自旋标记成像量化脑转移瘤放疗前后海马血流灌注变化
- Author:
Rui LIU
1
;
Guanzhong GONG
;
Shanshan DU
;
Kangning MENG
;
Ruozheng WANG
;
Yong YIN
Author Information
1. 山东第一医科大学(山东省医学科学院)研究生部,山东 济南 250000;山东省肿瘤防治研究院(山东省肿瘤医院)放射物理技术科,山东 济南 250117
- Publication Type:Journal Article
- Keywords:
hippocampus;
blood flow perfusion;
radiotherapy;
brain metastasis;
magnetic resonance imaging;
three-dimensional arterial spin labeling
- From:
Chinese Journal of Medical Physics
2025;42(2):148-153
- CountryChina
- Language:Chinese
-
Abstract:
Objective To retrospectively analyze the changes in cerebral blood flow(CBF)of hippocampus before and after radiotherapy(RT)and to explore its relationship with dose for providing a feasible approach for dynamically monitoring hippocampal response after whole brain radiation therapy in patients with brain metastases(BMs).Methods A retrospective analysis was conducted on magnetic resonance(MR)images from 43 BMs patients before and after RT,including T1-weighted imaging(T1WI)and three-dimensional arterial spin labeling(3D-ASL)imaging.Manual segmentation of the hippocampal structures was performed on T1WI to determine hippocampal volume,while CBF within the hippocampus was derived from 3D-ASL images.Patients were categorized into different groups according to the time interval between two MR scans and the dose received by the hippocampus,namely short time interval[<30 d,with an average of(19.74±7.15)d]≤1 Gy,1-30 Gy and≥30 Gy groups;long time interval[>3 months,with an average of(495.50±226.06)d]≤1 Gy,1-30 Gy and≥30 Gy groups.The patterns of changes in hippocampal CBF and volume,as well as the dose-effect relationship following RT were analyzed.Results(1)A total of 86 hippocampi were enrolled,showing reductions of 8.32%in minimum CBF(CBF-min),7.31%in maximum CBF(CBF-max),8.09%in mean CBF(CBF-mean),and 4.11%in hippocampal volume after RT(P<0.05).The decrease rates of CBF-min,CBF-max and CBF-mean were 6.33%,7.01%and 8.23%higher than the reduction rate of hippocampal volume,respectively.(2)With a brief interval between two MR simulation localization scans,hippocampal CBF in the groups receiving≤1 Gy and 1-30 Gy exhibited an increase,with the increase rate positively correlated to the radiation dose absorbed by the hippocampus.Conversely,in the group receiving≥30 Gy,hippocampal CBF decreased.The variations in the rate of hippocampal CBF change across the dose groups were statistically significant,except when comparing≤1 Gy and 1-30 Gy groups(P<0.05).Additionally,the hippocampal volume in all 3 dose groups experienced a slight increase,with the growth rate also positively correlated to the radiation dose received by the hippocampus;however,these differences were not statistically significant(P>0.05).(3)With a long interval between MR simulation localization scans,both hippocampal CBF and volume in all 3 dose groups demonstrated decreasing trends,with the decrease rate positively correlated to the radiation dose received by the hippocampus.Statistically significant differences in the rate of CBF change were noted among the dose groups,except for the comparison between≤1 Gy and 1-30 Gy groups(P<0.05).The reduction rate of hippocampal volume across 3 dose groups was statistically significant(P<0.05).Conclusion The reduction in hippocampal CBF following RT in BMs patients is more sensitive than the reduction in hippocampal volume,exhibiting a pronounced dependence on both time and radiation dose.Consequently,CBF changes should be employed as a standard bioindicator for monitoring the response to hippocampal RT and predicting radiological injuries after whole brain radiotherapy in BMs patients.
