Volume Changes in Normal-Appearing Gray Matter for Nasopharyngeal Carcinoma by Using MR Voxel-based Morphometry

Objective: To assess the radiation-induced gray matter (GM) volume differences between nasopharyngeal carcinoma (NPC) patients who had and had not received radiotherapy (RT). Methods: Differences in GM volume between 20 NPC patients after RT and 16 control patients with newly diagnosed but not yet medically treated NPC was assessed by using magnetic resonance imaging voxel-based morphometry (VBM). Results: Patients who had received RT had GM volume decreases in the bilateral middle temporal gyrus, left superior frontal gyrus and left inferior occipital lobular, cluster size >100 voxels. Conclusion: GM volume deficits in bilateral temporal lobes in patients who had received RT. VBM can detect the earlier GM alteration which conventional MR can not detect.