Patients with brain metastases from lymphoma, leukemia or small cell cancer should generally be given radiation therapy to the entire brain, although these tumors may also be treated with systemic chemotherapy.
    The standard approach with brain metastases of any other origin is to decide if the tumor can be removed. A CT scan or an MRI should be done to discover whether there is more than one tumor and to define the specific site in the brain where the tumor or tumors are located.
• If there is only one tumor and the patient's overall condition is good, surgical removal of the metastasis may be
  attempted, although factors such as location within the brain, the duration since the primary cancer was treated
  and the presence of metastases elsewhere in the body have to be considered. This approach gives the best
  short-term and long-term palliation. After the tumor is removed, radiation therapy is given to the entire brain.
• In patients with more than one brain metastasis, surgery is not usually an option and radiation is delivered to
  the entire brain.

Investigational 
• A method of biopsying or removing tumors called stereotaxic surgery is being studied. This allows for access to
  the brain tissue without causing extensive side effects ( see "BRAIN TUMORS: ADULT" ).
• An alternative to conventional surgery on a single or a small number of brain metastases is the "gamma knife."
  This is a type of radiation treatment delivered by a machine that focuses multiple radiation beams directly at
  the offending area. This technique is offered in certain centers in the United States.