The Role of Radiosurgery to the Tumor Bed After Resection of Brain Metastases

BACKGROUND: Optimal postoperative management paradigm for brain metastases remains controversial. OBJECTIVE: To conduct a systematic review of the literature to understand the role of postoperative stereotactic radiosurgery after resection of brain metastases. METHODS: We performed a MEDLINE search of the literature to identify series of patients with brain metastases treated with stereotactic radiosurgery after surgical resection. Outcomes including overall survival, local control, distant intracranial failure, and salvage therapy use were recorded. Patient, tumor, and treatment factors were correlated with outcomes through the use of the Pearson correlation and 2-way Student t test as appropriate. RESULTS: Fourteen studies involving 629 patients were included. Median survival for all studies was 14 months. Local control was correlated with the median volume treated with radiosurgery (r = -0.766, P < .05) and with the rate of gross total resection (r = .728, P < .03). Mean crude local control was 83%; 1-year local control was 85%. Distant intracranial failure occurred in 49% of cases, and salvage whole-brain radiation therapy was required in 29% of cases. Use of a radiosurgical margin did not lead to increased local control or overall survival. CONCLUSION: Our systematic review supports the use of radiosurgery as a safe and effective strategy for adjuvant treatment of brain metastases, particularly when gross total resection has been achieved. With all limitations of comparisons between studies, no increase in local recurrence or decrease in overall survival compared with rates with adjuvant whole-brain radiation therapy was found.