RADT-47. CLINICAL OUTCOMES AFTER SURGICAL RESECTION OF BRAIN METASTASES IN SMALL CELL LUNG CANCER PATIENTS

Abstract Small cell lung cancer (SCLC) has a high propensity to metastasize to the brain. Radiotherapy is the primary treatment for SCLC brain metastases. Whole brain radiotherapy (WBRT) has been the standard of care, but recent studies show similar overall survival (OS) in patients treated with upfront stereotactic radiosurgery (SRS). Surgery does not typically have a role in SCLC although it can provide relief of neurologic symptoms and pathologic diagnosis. We sought to determine the clinical outcomes of patients who underwent surgical resection of SCLC brain metastases. A retrospective chart review of SCLC patients treated at UPMC from 2010 – 2022 was performed. OS after resection was estimated using the Kaplan-Meier method with log-rank test. 4,213 patients were diagnosed with SCLC, of which 715 patients (17%) had synchronous brain metastases at initial diagnosis. Forty patients underwent resection of SCLC brain metastases, all of whom were symptomatic. The median diameter of the resected brain metastases was 3.8 cm (range 1.7 – 8 cm). Seventy-five percent (n=30) had resection of synchronous brain metastases and 25% (n=10) had resection of metachronous brain metastases. Median OS for the surgical cohort was 13.6 months (interquartile range (IQR), 3.4 – 21.9 months). Patients with metachronous and synchronous brain metastases had median OS of 6.8 months (IQR, 2.8 – 24.6 months) and 14.3 months (IQR, 3.6 – 20.4), respectively. Of patients with synchronous brain metastases (n=30), 53% (n=16) received post-operative WBRT, 40% (n=11) received post-operative SRS and 10% (n=3) died within 7 weeks of surgery. Median OS of patients with synchronous brain metastases treated with WBRT and SRS were 11.9 months (IQR, 3.8 – 21.7) and 19.0 months (IQR, 14.6 – 30.3), respectively, and the difference was not statistically significant (p=0.53). Surgery for SCLC brain metastases is uncommon. Patients who received SRS versus WBRT post-operatively for synchronous brain metastases had no difference in OS.