This year in the United States, it is estimated that over 80 000 people will likely be diagnosed with a brain or central nervous system tumor. Our findings indicate the Dxcover® Brain Cancer liquid biopsy has comparable performance to commercially available tests for other cancers. Here we present our results from machine learning models that have been tuned for greater sensitivity or specificity, since the precise trade-off between these statistics is likely to vary across international healthcare systems. A simple, rapid blood test that can be administered easily in a primary care setting would enable quicker referral to imaging for those who are most likely to have a brain tumor. This prospective, analyst-blinded clinical study demonstrates the clinical utility of a spectroscopic brain cancer liquid biopsy which can effectively triage symptomatic patients for investigative medical imaging for suspected brain tumors.