Outcomes of Combined Microsurgery and Stereotactic Radiosurgery for Motor Strip Brain Metastases.

Abstract

Primary motor cortex metastases (pMCM) often result in functionally impairing symptoms. The aim of this study was to determine the local control and functional outcomes of patients who underwent combined microsurgical resection followed by stereotactic radiosurgery (SRS) for pMCM. A retrospective review was performed to identify patients who received microsurgical resection followed by SRS for pMCM at a single institution between 2013 and 2021. Tumor volumes, treatment parameters, local control data, and functional motor scores using the Response Assessment in Neuro-Oncology Brain Metastases (RANO-BM) criteria were analyzed for a follow-up period of one year after treatment. Eleven patients who received microsurgical resection followed by SRS within 35 days were included in the analysis. Median SRS dose was 18 Gy to the 50% isodose line delivered in 1-3 fractions. The mean tumor volume was 13.2 cm³. All patients with follow-up data had stable or improved strength scores up to one year after treatment, with no patients showing disease progression, based on RANO-BM criteria at 3, 6, and 12 months after treatment. In this single-center case series, microsurgical resection followed by SRS for pMCM is safe and results in rapid and durable improvements in functional motor outcomes, particularly for patients with larger tumor sizes.