A Pilot/Phase II Study of Gamma Knife Radiosurgery for Brain Metastases Using 3Tesla MRI and Rational Dose Selection

The aims of this study are to pilot a study to measure local control after "rational dose" selected gamma knife radiosurgery for brain metastases and to measure treatment related toxicity for rational dose selected gamma knife radiosurgery for brain metastases. In addition, the quality of life and neurocognition of patients undergoing gamma knife radiosurgery will be measured using the validated European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-BN20 survey instruments. "Rational dose selection" is a concept wherein doses used for stereotactic radiosurgery is selected based on tumor volume, prior irradiation with whole brain radiotherapy, and the relative radioresistance of the tumor (radioresistant = melanoma, renal cell carcinoma, sarcoma; radiosensitive = breast cancer, lung cancer, colorectal cancer, gastrointestinal cancers). Eligible patients will have histologically confirmed cancer and MRI evidence of metastatic disease within the brain. Patients will be eligible for the trial if intracranial radiosurgery has been recommended for treatment of brain metastases. Patients will be excluded if they have an extremely radiosensitive tumor (leukemia, lymphoma), a radiosensitivity syndrome, a resection of a brain metastasis, or cannot tolerate the MRI or placement of a stereotactic head frame. All patients must sign informed consent. Radiation will consist of gamma knife radiosurgery delivered using doses selected based on the concept of "rational dose selection" as summarized above.