The authors have reviewed the experimental data on the radio-response of the central nervous system (CNS) and summarize the development of rational prevention strategies for radiation necrosis. Currently, radiation necrosis is thought to result from complex dynamic interactions between parenchymal and vascular endothelial cells within the CNS. The latent time, preceding the clinical manifestation of damage, is viewed as an active phase where cytokines and growth factors play important roles in inter- and intracellular communication. The present pathogenetic model forms the basis of rational innovative prevention strategies, which are now being studied in vivo. They include treatment with growth factors as well as neural stem cell transplantation and neoangiogenesis.