<qa>  What is the same type of scan?5. Patients must have shown unequivocal evidence for tumor progression by MRI or CT scan. A scan should be performed within 14 days prior to registration and on a steroid dose that has been stable for at least 5 days. If the steroid dose is increased between the date of imaging and registration a new baseline MRCT is required. The same type of scan, i.e., MRI or CT must be used throughout the period of protocol treatment for tumor measurement. 