LMD-15. Beyond cytologY - A single institution experience using CNSideTM for diagnosing and monitoring treatment response in Non-Small Cell Lung Cancer patients with Leptomeningeal Carcinomatosis (LMC)

Introduction Leptomeningeal Carcinomatosis (LMC) occurs in 3–9% of Non-Small Cell Lung Cancer (NSCLC) patients. Diagnosis of LMC includes clinical evaluation, imaging, and cytology. These have modest sensitivity and are inadequate for monitoring treatment response. Biocept’s CNSideTM is a proprietary assay utilizing a 10-antibody capture cocktail with microfluidic chamber that quantitatively detects tumor cells in the cerebrospinal fluid (CSF). Switch BlockerTM is a proprietary single gene assay that detects actionable mutations in the CSF. We describe a retrospective single institution experience using these assays in NSCLC patients with confirmed LMC or suspected LMC, treated between 2017 and 2021.