INCLUSION CRITERIA:

Patients must:

1. be 21 years of age or older.
2. have a histologically confirmed primary malignancy.
3. be able to undergo an MRI scan of the brain.
4. have one to three intraparenchymal brain metastases as identified on a brain MRI scan with intravenous contrast.
5. have contrast enhancing tumor(s) that are well circumscribed and less than or equal to 4.0 cm in any dimension.
6. be appropriate for either procedure as determined by both a neurosurgeon and a radiation oncologist.

EXCLUSION CRITERIA:

Patients must not:

1. have tumor(s) in the midbrain, pons, or medulla - patients undergoing surgical resections in these areas are highly likely to develop significant neurological deficits or death.
2. have tumors within 10 millimeters of the optic apparatus (nerves and chiasm) or the area postrema - patients undergoing SRS to these areas are at significant risk of developing permanent blindness or intractable nausea.
3. be poor operative candidates from an anesthetic point of view secondary to other major medical illnesses - the risk of undergoing general anesthesia outweighs the potential benefit of undergoing surgical resection of a brain metastasis.
4. have a coagulopathy demonstrated by an abnormal prothrombin time, activated partial thromboplastin time, or thrombocytopenia (platelet count less that 150,000 platelets/mm3) - the risk of developing uncontrollable intra-operatively bleeding outweighs the potential benefit of undergoing surgical resection of a brain metastasis.
5. have radiographic or cerebrospinal fluid specimen evidence of widespread leptomeningeal metastasis - neither surgery nor SRS is a useful treatment modality for this condition.
6. significant psychiatric impairments which, in the opinion of the investigators, will interfere with the proper administration or completion of the protocol - self explanatory.
7. acute or untreated infections (viral, bacterial or fungal) - patients with active infections are highly likely to have spread of their infections to the brain as a result of a craniotomy.
8. be pregnant at the time of the randomized treatment - general anesthesia and surgery may subject the fetus to unacceptable risks. Also, the NIH does not offer full obstetrical services in the event that medical care to the mother and/or fetus is required. Pregnant women presenting with brain metastases will be referred to facilities offering OB/GYN services.
9. be prisoners or other institutionalized individuals - these individuals are at risk of being susceptible to undue influences to participate in a research protocol against their free will.
10. have a diagnosis of germ cell tumor, lymphoma or small cell lung cancer - these tumors are highly radiosensitive and should therefore be treated with radiation.
11. have any of the following: aneurysm clip, implanted neural stimulator, implanted cardiac pacemaker or auto defibrillator, cochlear implant, ocular foreign body or implant [e.g. metal shavings, retinal clips], or insulin pump as these items would be contra-indications to undergoing an MRI scan.
12. have an allergy to iodine or shellfish or have previously had an allergic reaction to iodinated-contrast agents as this is a contra-indication to undergoing a contrast enhanced CT of the brain - a contrast enhanced CT of the brain is required for the planning of SRS.