Fig. 4From: A comparative study of dose distribution of PBT, 3D-CRT and IMRT for pediatric brain tumors a Average normal brain dose for each treatment plan with sphere targets with the same iso-center as the brain center and different diameters (2, 3, 4, 6 cm). b Correlation between target size and difference in normal brain dose in PBT compared to 3DCRT or IMRTBack to article page