Approximately 20-40% of patients with systemic malignancies develop brain metastases. There appears to be a trend toward an increasing incidence of brain disease, and patients with systemic malignancies can live longer because of earlier diagnosis and/or better treatment. Many brain tumors are now identified in asymptomatic patients as part of screening neuroimaging studies. The two most commonly used treatments, whole-brain radiation therapy (WBRT) and stereotactic radiosurgery (SR), extend survival from 3 months to 5 months and from 7 months to 13 months, respectively, depending on tumor type.

Surgical resection can be a valuable approach for patients with larger symptomatic tumors. Although the value of radiosurgery in obtaining local tumor control and extending survival compared with WBRT alone has been substantiated, the status of long-term survivors and the reasons for their better outcome remain unclear. Numerous studies have confirmed that the extent of extracranial disease correlates directly with survival. What remains unclear is whether successful or unsuccessful care for systemic malignancy, together with aggressive brain tumor care, can lead to prolonged survival. We are faced with the challenge of improving survival for patients with brain metastases and managing late complications or recurrences that previously were unseen as our overall management of cancer improves.

Stereotactic radiosurgery, with or without whole-brain radiation therapy, has become a valued management choice for patients with brain metastases, although their median survival remains limited. In patients who receive successful extracranial cancer care, patients who have controlled intracranial disease are living longer. The authors evaluated all brain metastasis in patients who lived for 4 years after radiosurgery to determine clinical and treatment patterns potentially responsible for their outcome.

METHODS
Six hundred seventy-seven patients with brain metastases underwent 781 radiosurgery procedures between 1988 and 2000. Data from the entire series were reviewed; and, if patients had 4 years of survival, then they were evaluated for information on brain and extracranial treatment, symptoms, imaging responses, need for further care, and management morbidity. These long-term survivors were compared with a cohort who lived for < 3 months after radiosurgery (n = 100 patients).

RESULTS
Forty-four patients (6.5%) survived for > 4 years after radiosurgery (mean, 69 mos with 16 patients still alive). The mean age at radiosurgery was 53 years (maximum age, 72 yrs), and the median Karnofsky performance score (KPS) was 90. The lung (n = 15 patients), breast (n = 9 patients), kidney (n = 7 patients), and skin (melanoma; n = 6 patients) were the most frequent primary sites. Two or more organ sites outside the brain were involved in 18 patients (41%), the primary tumor plus lymph nodes were involved in 10 patients (23%), only the primary tumor was involved in 9 patients (20%), and only brain disease was involved in 7 patients (16%), indicating that extended survival was possible even in patients with multiorgan disease. Serial imaging of 133 tumors showed that 99 tumors were smaller (74%), 22 tumors were unchanged (17%), and 12 tumors were larger (9%). Four patients had a permanent neurologic deficit after brain tumor management, and six patients underwent a resection after radiosurgery. Compared with the patients who had limited survival (< 3 mos), long-term survivors had a higher initial KPS (P = 0.01), fewer brain metastases (P = 0.04), and less extracranial disease (P < 0.00005).

CONCLUSIONS
Although the expected survival of patients with brain metastases may be limited, selected patients with effective intracranial and extracranial care for malignant disease can have prolonged, good-quality survival. The extent of extracranial disease at the time of radiosurgery was predictive of outcome, but this does not necessarily mean that patients cannot live for years if treatment is effective.

MRI Images of Patients 5 Years after Gamma Knife for Brain Metastases