Expanding Indications for Stereotactic Radiosurgery in the Treatment of Brain Metastases

Surgical neuro-oncology tends to be focused on primary brain tumors (those originating within the cranium). However, each year in the United States, only 20 000 new primary brain tumors are diagnosed. In contrast, > 200 000 new metastatic brain tumors are seen annually. The most common primary tumors are lung, breast, kidney, gastrointestinal, and melanoma. Twenty percent to 40% of all cancer patients will develop a metastatic brain tumor sometime during the course of their illness. These tumors will be multiple 60% to 70% of the time; the remainder are solitary. The overall incidence of brain metastases is increasing, probably because treatment of the primary tumors has improved, leading to longer life expectancies and hence longer times during which a brain metastasis can develop.

Historically, the treatment of metastatic brain tumors has been very nihilistic. Best supportive care leads to a...