- Patients must have a previously histologically or cytologically confirmed glioma (astrocytic or oligodendroglial supratentorial tumors grades 2, 3 or 4 according to the WHO 2007 classification 82) that has been previously treated with fractionated radiation therapy and now shows evidence of recurrence. There is no limit regarding the number / type of previous therapies that the patient has received for glioma, aside from exceptions mentioned below. If the brain tumor is in an eloquent location (e.g. brain stem) a clinical diagnosis is sufficient.