Objectives: Three-dimensional Arterial Spin Labeling (ASL) and Voxel-Based Morphometry (VBM) methods were used to demonstrate whole-brain perfusion and gray matter volume abnormalities after Radiotherapy (RT) for Nasopharyngeal Carcinoma (NPC).
Methods: Fifty participants with NPC were divided into Pre-RT Control (PC), Acute Reaction Period (ARP), and Delayed Reaction Period (DRP) groups based on the course of RT. A Region of Interest (ROI) based analysis was performed on the Cerebral Blood Flow (CBF) and anatomic data.
Results: Compared with the PC group, increased perfusion in the left cerebellum, left paracentral lobule, and bilateral thalamus was noted in the ARP group (p<0.05), while patients in the DRP group showed no significant differences when compared to the other two groups (p>0.05). The relative Gray Matter Volume (rGMV) was decreased in the right paracentral lobule in the ARP group, but increased in the bilateral cerebellum in the DRP group compared to the PC group, and increased in the left cerebellum, bilateral cerebellum and right paracentral lobule in the ARP group as well (all p<0.05). Moreover, the CBF was negatively correlated with the rGMV in several specific brain areas (p<0.05).
Conclusion: ASL facilitated non-invasive detection of radiation-induced whole-brain gray matter perfusion changes, which were transient, dynamic, complicated, and negatively correlated with the GMV.