Stereotactic radiosurgery to the resection cavity of brain metastases: a retrospective analysis and literature review.

Purpose: The aim of this study was to analyze results of stereotactic radiosurgery (SRS) as adjuvant therapy for resected brain metastases.

Methods: Medical records of patients treated at a single institution with SRS to the postoperative cavity of brain metastases were retrospectively reviewed. Patients who completed the prescribed SRS regimen following gross-total resection and had no previous whole brain radiotherapy were included in the study. Kaplan-Meier analyses were used to estimate local (LC) and intracranial control (IC), and overall survival (OS) rates.

Results: Between April 2005 and July 2010, 77 patients (median age 63 years) with 89 metastases met the inclusion criteria. The median prescription dose was 18 Gy (12-27 Gy) delivered in 1-3 fractions for a median target volume of 7.6 cm(3) (0.5-59 cm(3)). The 6-month, 1-year, and 2-year LC rates were 76.1, 76.1, and 74.3%, respectively. The 6-month, 1-year, and 2-year IC rates were 75.2, 54, and 43.6%, respectively. With a median follow-up of 13.8 months, the median OS was 14.5 months (1.9-51.4 months) after SRS. The overall 6-month, 1-year, and 2-year OS rates were 91, 62.5, and 43.6%, respectively. Complications included 2 patients with radiation necrosis.

Conclusion: Adjuvant radiosurgery to the tumor cavity of resected brain metastases is well-tolerated and achieves LC in the majority of patients.