Salvage therapy with Gamma Knife Surgery (GKS) for selective removal of the tumor (as opposed to whole-brain radiotherapy) has been shown to modestly improve the median survival of patients with recurrent GBM, particularly when administered adjunctively to standard chemotherapy and immunotherapy (anti-vascular endothelial growth factor (VEGF) and a monoclonal antibody, bevacizumab (Avastin®) [6]. This evidence concerns the gene VEGFA and neoplasm.