Published in the Green Journal, this paper by the Dresden group studied diffusion imaging which has been shown to be a sensitive method to detect early changes in the cerebral white matter (WM) after radiation, and compared the changes in the mean diffusivity (MD) of WM in glioblastoma patients treated with proton (n=20) and photon (n=50) irradiation. A significant decrease of MD (p < 0.05) in WM regions receiving more than 20 Gy was observed for both types of irradiations. In patients treated with photons, significant reductions of MD in the entire WM (p < 0.05) were seen at all time points, however whole brain MD did not change significantly in proton patients. The authors suggested further investigations to assess whether those MD changes correlate with known radiation induced side-effects.