Abstract #2708

Qiu D, Khong P, Chan G, Leung L, Kwong D, Cao G

We describe a method to map whole brain radiation dose distribution calculated from radiotherapy planning onto diffusion tensor MR fractional anisotropy (FA) images to study voxel-by-voxel, dose-effect relationships and regional differences to radiation in medulloblastoma survivors. The method was validated on two normal control subjects and applied to two medulloblastoma survivors who had sequential MR scans over a one year period. Dose dependant FA reduction was found in both patients and regional susceptibility of brain regions was also observed. We conclude that the method described is useful in the study of radiation induced brain injury.