Due to longer survival and a better performance status, patients often reach a point at which re-treatment is feasible. Treatment options for recurrent glioblastoma and anaplastic glioma can include surgery, chemotherapy and re-irradiation. Re-irradiation of patients with recurrent high grade glioma is slowly becoming standard of care. It provides a comparable overall survival to palliative chemotherapy. In case of GBM there is a median time to progression after treatment of 20-27 weeks and a MOS of 26 to 60 weeks.