Abstract #3644

Regional Variation in White Matter Diffusion Index Changes Following Chemoradiotherapy: A Prospective Study Using Tract-Based Spatial Statistics

Christopher H. Chapman¹, Mohammad Nazem-Zadeh¹, Oliver Lee², Matthew Schipper¹, Christina I. Tsien¹, Theodore S. Lawrence¹, Yue Cao¹,³

¹Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, United States; ²Department of Biostatistics, University of Michigan, Ann Arbor, MI, United States; ³Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States

We examined regional variation in DTI changes following chemoradiotherapy. The largest fractional anisotropy decreases were seen in the cingula, fornix, and corpus callosum. This pattern of selective white matter degradation may be related to specific neurocognitive impairments commonly seen following treatment. Radial and axial diffusivity changes were temporally and spatially separated, supporting their use as specific markers of distinct pathological processes.