Background: Brain metastases are the most common type of intracranial tumor. Until recently, whole brain fractionated radiation therapy (WBRT) was the mainstay of treatment, thereby confining the role of neurosurgeons to resection of an occasional solitary, accessible, and symptomatic brain metastasis. Median survival after surgery and radiation typically ranged from 5 to 11 months.
Methods: We analyzed various demographic incidence reports and our series of brain metastasis patients treated with radiosurgery. During a 15-year interval (1987-2002), radiosurgery was performed on 5,032 patients of whom 1,088 (21.6%) had metastatic brain tumors.
Results: In the United States, 266,820 to 533,640 new cases of brain metastases will be diagnosed in the year 2003. Evidence to date demonstrates that radiosurgery provides effective local tumor control for brain metastases. Important prognostic factors affecting patient survival include the absence of active systemic disease, the patient's preoperative performance status, age, and the number of metastases. Survival and local tumor control rates attained with radiosurgery are superior to those of either conventional surgery or WBRT. The morbidity associated with radiosurgery of brain metastasis is very low, and the mortality rate approaches zero.
Conclusions: Compelling evidence indicates that radiosurgery is an effective neurosurgical management strategy for intracranial brain metastases. Quite often, favorable tumor control and survival can be achieved without WBRT. With radiosurgery as a therapeutic option, neurosurgeons now have a vastly expanded armamentarium for treatment of patients with brain metastases. The large number of patients with brain metastases who require care by a neurosurgeon for optimal treatment has significant implications for both the patterns of neurosurgical training and practice in the United States.