Clinician perspectives on the clinical utility of Belay Summit™ 2.0 cerebrospinal fluid test – A mixed methods study

Purpose: National Comprehensive Cancer Network (NCCN) Central Nervous System (CNS) Guidelines recommend utilizing next-generation sequencing (NGS) to enable comprehensive genomic profiling (CGP) as standard of care for molecular characterization of CNS malignancies. The restrictive nature of the blood-brain barrier (BBB) makes plasma-based liquid biopsy an ineffective alternative, however cerebrospinal fluid (CSF)-based liquid biopsy offers a minimally invasive alternative for genomic assessment. This study aimed to evaluate the clinician perspective of clinical utility of Belay's CSF-based genomic assay, Summit™ 2.0, and to assess how clinicians use test results in routine clinical practice. Methods: Clinical utility was assessed using clinician-reported survey responses from cases where Summit™ 2.0 testing was ordered for patients with known or suspected CNS disease. Survey questions evaluated indications for testing, test positivity, impact on clinical decision-making, report clarity, and perceived overall utility. Results: The survey response rate was 52% (95 surveys sent). Among 49 surveyed cases, 74% yielded positive genomic findings. Clinicians most frequently ordered testing to address diagnostic uncertainty or inform clinical management, with treatment selection as a less frequent primary indication. Clinical utility was reported in 86% of cases including those with negative findings, of which some results were useful for confirming existing diagnoses or management strategies. Clinicians also reported high confidence in the clarity and usability of test reports. Conclusion: Clinician-reported outcomes indicate that Summit™ 2.0 CSF-based genomic testing influenced clinical decision-making, including treatment selection, diagnostic clarification, confirmation of expected diagnoses, and care planning and provides meaningful information that supports diagnostic evaluation and management of CNS tumors.