Feasibility of Intraoperative Microdialysis During Neurosurgery for Central Nervous System Malignancies

PRIMARY OBJECTIVE:

I. Determine biomarkers of in situ gliomas across a diverse patient cohort using intra-operative microdialysis to sample extracellular metabolites.

SECONDARY OBJECTIVE:

I. Evaluate the yield and specificity of microdialysate D-2HG as a candidate tumor biomarker to differentiate between IDH-mutated and IDH-wildtype gliomas.

II. Identify biomarkers of tumor-associated processes including brain edema, brain infiltration with non-enhancing tumor, and tumor-associated hypoxia or necrosis.

III. Determine the contribution of blood-brain barrier disruption to metabolite abundance within enhancing gliomas.

EXPLORATORY/CORRELATIVE OBJECTIVES:

I. Perform untargeted metabolomics of tumor microdialysate to elucidate extracellular biomarkers reflective of human central nervous system malignancy subtype, grade, and tumor region.

II. Banking of microdialysate specimens for future analyses.

OUTLINE:

Patients undergo microdialysis over 30 minutes during standard of care biopsy or resection.

After completion of study, patients are followed up for 42 days.

Inclusion criteria

• Age >= 18 years
• Diagnosis of the following, based on clinical and radiographic evidence:

• Any glioma
• Metastatic brain tumor of any primary origin
• Epileptic focus requiring surgical resection
• Planned neurosurgical procedure for purposes of biopsy or resection of suspected or previously diagnosed brain tumor (primary or metastatic) or epileptic focus as part of routine clinical care
• Willing to undergo neurosurgical resection or biopsy at Mayo Clinic (Rochester, Minnesota [MN])
• Ability to understand and the willingness to sign a written informed consent document

Exclusion criteria

• Vulnerable populations: pregnant women, prisoners or the mentally handicapped
• Patients who are not appropriate candidates for surgery due to current or past medical history or uncontrolled concurrent illness