Diagnostic accuracy of cerebrospinal fluid liquid biopsy and MRI for leptomeningeal metastases in solid cancers: A systematic review and meta-analysis.

BACKGROUND

Cerebrospinal fluid (CSF) cytology remains the gold standard approach for diagnosing of leptomeningeal metastases (LM), but has clinical problems due to its low sensitivity. This systemic review and meta-analysis evaluated the diagnostic accuracy of the novel CSF biomarkers of liquid biopsy and magnetic resonance imaging (MRI) for detecting LM in patients with solid cancers.

METHODS

A systematic search of electronic databases was conducted to identify all published diagnostic accuracy studies on CSF liquid biopsies and MRI since January 2000 with registration for PROSPERO (#CRD42022301988). Articles were selected based on pre-defined inclusion and exclusion criteria following the PRISMA 2020 statement.

RESULTS

The search yielded 3790 citations, and 10 studies with 668 patients were included in the final analysis. The pooled prevalence of LM was 50.9% (340/668). The respective sensitivity and specificity for index tests were as follows: circulating tumor cells (CTC), 87.0% (95% confidence interval [CI] 77.9-92.6%) and 93.8% (86.9-97.2%); cell-free tumor DNA, 97.9% (19.3-100%) and 89.0% (25.3-99.5%); MRI 59.4% (60.7-76.9%) and 97.6% (77.3-99.8%); cytology, 71.9% (54.7-82.9%) and 100%. The diagnostic odds ratio was 100.6 (29.38-344.09) for CTC and 93.3 (88.42-1034.05) for MRI.

CONCLUSION

Novel CSF liquid biopsies and MRI may offer improved diagnostic accuracy for LM from solid cancers; however, further research is required to specify the threshold values and to construct standards for individual primary cancers.