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

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. (C) 2020 Societe francaise de radiotherapie oncologique (SFRO). Published by Elsevier Masson SAS. All rights reserved.

Automated summary

This study systematically reviewed the brain microstructure changes in NPC patients following radiotherapy, finding that changes were most consistent in the temporal region and correlated with latency following treatment. It also highlighted reduced FA and GM measures in certain brain areas beyond the irradiation site.