Clinical Resources

Belay offers a growing portfolio of CSF liquid biopsy tests for CNS tumor profiling.


Explore our tests →
View our latest news →
Contact our team →

Clinician Perspectives on Clinical Utility of Belay Summit 2.0 Cerebrospinal Fluid Test – A Mixed Methods Study

Authors:

Matthias Holdhoff, Chen Hu, Vindhya Udhane, DeElegant Robinson, Alexandra Larson, Qian Nie, Kala F. Schilter, Chetan Bettegowda, Honey V. Reddi

Journal:

Abstract:

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 Belay 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 Belay 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.

Figure 1: Overview of Belay Summit 2.0 results for 49 cerebrospinal fluid (CSF) specimens.

Pie chart showing 37% primary and 63% metastatic CNS specimens, paired with a bar chart of Belay Summit 2.0 positive/negative results by tumor origin: primary 10 positive/8 negative, metastatic 26 positive/5 negative.

(A) Primary tumors accounted for 37% of specimens (gray), while 63% were metastatic specimens (black), distributed across positive and negative results.

Stacked bar chart of Belay Summit 2.0 positive and negative results by tissue of origin, including glioma, breast carcinoma, lung cancer (NSCLC), melanoma, and other primary and metastatic CNS diagnoses.

(B) Distribution of positive and negative Belay Summit 2.0 results among suspected primary or metastatic central nervous system (CNS) disease, stratified by tissue of origin.

Figure 2: Clinical use and impact of Belay Summit 2.0 CSF liquid biopsy testing.

Map of the United States showing the geographic distribution of survey respondents by state, including Illinois (3), Texas (2), Florida (2), and one respondent each in several other states.

(A) Geographical representation of survey respondents.

Bar chart of reported indications for ordering Belay Summit 2.0 testing: diagnostic uncertainty (27), inform clinical management (24), treatment selection (16), and treatment monitoring (7).
Pie chart showing Belay Summit 2.0 results influenced clinical decision-making in 86% (42) of cases, did not in 8% (4), with 6% (3) unsure.

(B) Reported indications for ordering Belay Summit 2.0 testing, including diagnostic uncertainty (n = 27), clinical management (n = 24), treatment selection (n = 16), and disease monitoring (n = 7). (C) Proportion of cases in which Belay Summit 2.0 results influenced clinical decision-making (86%), did not influence decisions (8%), or had an uncertain impact (6%).

Pie chart of cases where test results influenced care, with an expanded bar chart of specific impacts: guided treatment choice (22), informed patient/caregiver decision-making (21), informed prognosis (18), led to definitive diagnosis (17), confirmed expected diagnosis (15), prompted referral (7), changed radiation therapy plan (7), led to additional testing (3), and avoided biopsy/surgery/resection (1).

(D) Reported clinical impact among cases in which test results influenced care, including treatment guidance (n = 22), patient or caregiver decision-making (n = 21), prognostic information (n = 18), definitive diagnosis (n = 17), confirmation of expected diagnosis (n = 15), referral to another specialty (n = 7), changes to therapy planning (n = 7), additional diagnostic testing (n = 3), and avoidance of biopsy or surgery (n = 1).

Pie chart of cases with no or uncertain clinical impact, with an expanded bar chart of reasons cited: result was unclear or uninformative (3 in the 'No' group, 1 in the 'Unsure' group), result confirmed treatment/management plan (1), and no response (2).

(E) Reported reasons for lack of or uncertainty in clinical impact were most commonly attributed to unclear or uninformative results.

Figure 3: Clinician-reported clinical utility and report clarity of Belay Summit 2.0.

3D bar chart of clinician agreement on the clinical utility of Belay Summit 2.0, showing Neutral (n=5), Agree (n=6), and Strongly Agree (n=38) responses, each split into positive and negative test results.

(A) Clinician responses regarding the clinical utility of Belay Summit 2.0 testing, categorized as Neutral (n = 5; 1 negative, 4 positive cases), Agree (n = 6; 1 negative, 5 positive cases), and Strongly Agree (n = 38; 11 negative, 27 positive cases).

Stacked bar chart of clinician agreement on the clarity of Belay Summit 2.0 test reports, showing Neutral (n=1), Agree (n=11), Strongly Agree (n=34), and No response (n=3), split by positive and negative results.

(B) Clinician responses regarding clarity and understandability of Belay Summit 2.0 test reports, categorized as Neutral (n = 1, negative case), Agree (n = 11; 4 negative, 7 positive), Strongly Agree (n = 34; 8 negative, 26 positive), and no response (n = 3, positive cases).

Donut chart showing 96% (47) of clinicians would order Belay Summit 2.0 again, with 4% (2) giving no response.

(C) Clinician responses regarding likelihood of ordering the test again, with 47 clinicians responding “Yes” (96%) and 2 clinicians provided no response.