Patients must have evidence for tumor progression by MRI or computed tomography (CT) scan. This scan should be performed within 14 days prior to registration and on a fixed dose of steroids for at least 5 days. If the steroid dose is increased between the date of imaging and registration a new baseline magnetic resonance (MR)/CT is required. The same type of scan, i.e., MRI or CT must be used throughout the period of protocol treatment for tumor measurement.