Dynamic Changes of Cortical Microstructure in Nasopharyngeal Carcinoma Patients After Radiotherapy: A Multi-Shell Diffusion Imaging Study

Motivation: Radiotherapy for nasopharyngeal carcinoma induces brain structural abnormalities, altering cortical microstructure. Goal(s): Longitudinally explore dynamic cortical microstructure changes over one year after Radiotherapy. Approach: We performed GM-based spatial statistics analysis (GBSS) on DTI and NODDI data, utilizing nonparametric permutation inference to identify dynamic alterations in diffusion metrics. Cortical regions were located in gray matter clusters by referring to the Desikan-Killiany atlas. Results: Bilateral temporal lobe MD reduced significantly, and NDI increased notably at six months post-RT, and these changes remained with larger clusters at 12 months. The affected gray matter regions included the entorhinal cortex, temporal pole, inferior temporal gyrus, and fusiform gyrus. Impact: The combination of DTI and NODDI allows for a more comprehensive understanding of the patterns of cortical microstructural changes induced by RT, offering the potential for early interventions in radiation-induced brain injury.