 - Prior radiation therapy - patients may have been treated with standard external beam radiation, interstitial brachytherapy, or radiosurgery in any combination. An interval of 4 weeks 28 days must have elapsed from the completion of radiation therapy to study entry and there must be subsequent evidence of tumor progression. Patients with prior interstitial brachytherapy or stereotactic radiosurgery must have confirmation of true progressive disease rather than radiation necrosis based on PET, MR spectroscopy or surgical documentation of disease. 