MRI-based brain structural changes following radiotherapy of Nasopharyngeal Carcinoma: A systematic review

Abstract

Purpose: Nasopharyngeal carcinoma (NPC) radiotherapy (RT) irradiates parts of the brain which may cause cerebral tissue changes. This study aimed to systematically review the brain microstructure changes using MRI-based measures, diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI) and voxel-based morphometry (VBM) and the impact of dose and latency following RT.

Methods: PubMed and Scopus databases were searched based on PRISMA guideline to determine studies focusing on changes following NPC RT.

Results: Eleven studies fulfilled the inclusion criteria. Microstructural changes occur most consistently in the temporal region. The changes were correlated with latency in seven studies; fractional anisotropy (FA) and gray matter (GM) volume remained low even after a longer period following RT and areas beyond irradiation site with reduced FA and GM measures. For dosage, only one study showed correlation, thus requiring further investigations.

Conclusion: DTI, DKI and VBM may be used as a surveillance tool in detecting brain microstructural changes of NPC patients which correlates to latency and brain areas following RT.

Keywords: Brain; Carcinome nasopharyngé; Cerveau; Diffusion Kurtosis Imaging; Diffusion Tensor Imaging; Imagerie Kurtosis de diffusion; Imagerie du tenseur de diffusion; Morphométrie à base de voxel; Nasopharyngeal Carcinoma; Voxel-Based Morphometry.