3. (2. continued) Patients with prior therapy that included interstitial brachytherapy, Gliadel wafers or stereotactic radiosurgical procedures must have confirmation of true progressive disease rather than radiation necrosis. Such confirmation may be using advanced imaging studies (e.g. PET scans, diffusion-perfusion MRI, SPECT etc) or if available, surgical sampling and histological confirmation (surgery is not required).