Three or More Courses of Stereotactic Radiosurgery for Patients with Multiply Recurrent Brain Metastases

BACKGROUND: Although patients with brain metastasis are treated with primary stereotactic radiosurgery (SRS), the use of salvage therapies and their consequence remains understudied. OBJECTIVE: To study the intracranial recurrence patterns and salvage therapies for patients who underwent multiple SRS courses. METHODS: A retrospective review was performed of 59 patients with brain metastases who underwent >= 3 SRS courses for new lesions. Cox regression analyzed factors predictive for overall survival. RESULTS: The median age at diagnosis was 52 years. Over time, patients underwent a median of 3 courses of SRS (range: 3-8) to a total of 765 different brain metastases. The 6-month risk of distant intracranial recurrence after the first SRS treatment was 64% (95% confidence interval: 52%-77%). Overall survival was 40% (95% confidence interval: 28%-53%) at 24 months. Only 24 patients (41%) had a decline in their Karnofsky Performance Status <= 70 at last office visit. Quality of life was preserved among 77% of patients at 12 months, with 45% experiencing clinically significant improvement during clinical follow-up. Radiation necrosis developed in 10 patients (17%). On multivariate analysis, gender (males, Hazard Ratio [HR]: 2.0, P < .05), Karnofsky Performance Status <= 80 (HR 3.2, P < .001), extracranial metastases (HR: 3.6, P < .001), and a distant intracranial recurrence <= 3months from initial to repeat SRS (HR: 3.8, P < .001) were associated with a poorer survival. CONCLUSION: In selected patients, performing >= 3 SRS courses controls intracranial disease. Patients may need salvage SRS for distant intracranial relapse, but focal retreatments are associated with modest toxicity, do not appear to negatively affect a patient's performance status, and help preserve quality of life.