CLRM-01 DETERMINANTS OF SYMPTOMATIC INTRACRANIAL PROGRESSION FOLLOWING AN INITIAL STEREOTACTIC RADIOSURGERY COURSE

Abstract To determine the prognostic significance of neurologic symptoms at progression for patients with brain metastases (BM) undergoing stereotactic radiosurgery (SRS), all patients completing an initial course of SRS between 1/2015 and 12/2020 were identified across two institutions. Intracranial progression (ICP) was recorded, with symptomatic ICP (SICP) defined as new/worsening neurologic symptoms without another etiology. Overall survival (OS), freedom from ICP (FFICP), and freedom from symptomatic ICP (FFSICP) were assessed via Kaplan-Meier method. For FFSICP, patients were censored at time of death or asymptomatic ICP. Logistic regression models tested parameter association to neurologic symptoms. Cox proportional hazard models tested parameters impacting FFICP and FFSICP. Among 1383 patients, median age was 63.4 years, 54.8% were female, and 45.6% had KPS ≥90. Common primary sites were non-small cell lung (48.7%), breast (14.7%), and melanoma (8.5%). 46.9% had oligometastatic disease (≤5 foci), and 53.4% had >1 BM. 26.1% patients had prior surgical resection, and 10.3% had WBRT. With a median follow up of 8.7 months, 504 (36%) and 194 (14%) experienced asymptomatic and symptomatic ICP respectively. OS was worse for patients experiencing SICP (median 10.2 vs 17.9 months, p