Detection of Leptomeningeal Disease Using Cell-Free DNA from Cerebrospinal Fluid.

Key Points Question Can cell-free DNA analysis of cerebrospinal fluid provide additional diagnostic utility beyond cytologic assessment? Findings In this diagnostic study of 43 cerebrospinal fluid samples from 22 patients with leptomeningeal disease confirmed by cytologic assessment who did not have parenchymal tumors abutting their cerebrospinal fluid, tumor-derived cell-free DNA was detected in the cerebrospinal fluid of 40 (93%) samples, whereas 31 (72%) of the samples were positive for malignant neoplasm as determined by cytologic analysis, a significant difference. Meaning These findings suggest that cerebrospinal fluid cell-free DNA analysis may be more sensitive than cytologic analysis for diagnosing leptomeningeal disease.