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

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

The purpose of this study is to collect prospective data for use as a comparator for future subsequent studies attempting to increase the efficacy or reduce the toxicity of gamma knife radiosurgery.

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.

Inclusion Criteria:

• Patients must have histologically or cytologically confirmed malignancy (not leukemia or lymphoma). There must be metastatic brain disease apparent on magnetic resonance imaging which offers a medical indication for brain radiation. - Age > 18
• Karnofsky Performance Status > 70
• MRI performed within 4 weeks of trial enrollment
• Medical oncologist or consenting physician verifies that chemotherapy options exist after treatment with intracranial therapy, and that chemotherapy is planned to initiate after completion of radiation. Or, survival as estimated by the medical oncologist or enrolling physician is > 3 months.

Exclusion Criteria:

• Extremely radiosensitive tumor (lymphoma, leukemia)
• Radiosensitivity syndrome (scleroderma, dermatomyositis, other genetic syndrome that predisposes to adverse radiotherapy complications)
• Evidence of leptomeningeal dissemination
• Resection of brain metastases, otherwise untreated with radiation for those brain lesions (presenting for postoperative consolidative radiotherapy)
• Presence of a medical device (pacemaker, stent) or allergy that precludes contrast enhanced MRI
• Patient is unable to tolerate placement of a stereotactic headframe
• Pregnancy