Rapid test of cerebrospinal fluid decreases time to diagnosis for brain tumors

### Rapid Test of Cerebrospinal Fluid Speeds Up Brain Tumor Diagnosis

**Summary:**

A new genotyping test that detects genetic markers of brain cancers in cerebrospinal fluid can significantly reduce the time required for diagnosis and eliminate the need for invasive brain biopsies in some patients. Developed by experts in neurosurgery, cancer, and pathology at Mass General Brigham, this rapid test can identify key mutations associated with brain tumors from samples obtained through lumbar puncture.

**Full Story:**

A collaborative effort among neurosurgery, cancer, and pathology specialists at Mass General Brigham has resulted in a groundbreaking genotyping test. This test, known as TetRS (Targeted Rapid Sequencing), can detect mutations linked to brain cancers from cerebrospinal fluid samples, decreasing the diagnosis time and potentially avoiding the need for invasive brain biopsies. The test was evaluated on 70 patients at Massachusetts General Hospital with central nervous system (CNS) lesions of unknown origin. It successfully identified mutations in 42% of patients with tumors, including cases of primary and secondary CNS lymphoma, glioblastoma, and gliomas, and has been published in the journal *Blood*.

"Speed is crucial in diagnosing brain and spinal cord tumors, which often present with rapidly progressive symptoms," said Dr. Ganesh Shankar, corresponding author and neurosurgeon at Massachusetts General Hospital. "Our test has reduced diagnosis times from 10 days to just 2 days, allowing quicker and less invasive treatment for patients."

TetRS, designed to identify specific genetic mutations unique to brain cancers, has shown a 100% specificity rate, indicating no false positives among the 37 patients without neoplasms. This rapid diagnostic tool has already been implemented across the Mass General Brigham network, enhancing patient care by allowing faster initiation of individualized treatments.

**Journal Reference:**

Gupta, M., Bradley, J., Massaad, E., et al. (2024). Rapid Tumor DNA Analysis of Cerebrospinal Fluid Accelerates Treatment of Central Nervous System Lymphoma. *Blood*. DOI: 10.1182/blood.2024023832

**Funding:**

This research was funded by the National Institutes of Health (NIH), The Darwin Project, and the Brian D. Silber Memorial Fund.