Liquid biopsy in the setting of leptomeningeal metastases: a systematic review and meta-analysis.

Purpose: The blood-brain barrier can prevent circulating tumor DNA (ctDNA) derived from the central nervous system from entering the blood making it challenging to evaluate molecular features of leptomeningeal metastasis (LM). Accordingly, we sought to systematically compare the diagnostic power or significance of ctDNA derived from cerebrospinal fluid (CSF) compared to plasma ctDNA in patients with LM.

Methods: A systematic review and meta-analysis was performed under the PRISMA guideline.