Feasibility of Intraoperative Microdialysis During Neurosurgery for Central Nervous System Malignancies

Study Overview
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Brief Summary
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This clinical trial evaluates the use of microdialysis catheters during surgery to collect biomarkers, and studies the feasibility of intraoperative microdialysis during neurosurgery for central nervous system malignancies. A biomarker is a measurable indicator of the severity or presence of disease state. Information collected in this study may help doctors to develop new strategies to better diagnose, monitor, and treat brain tumors.

Detailed Description
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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. IV. Determine the feasibility of detecting stable-isotope labeled metabolites in human microdialysate. 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.

Official Title
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Intraoperative Microdialysis During Neurosurgery for Central Nervous System Malignancies

Conditions
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Anaplastic Astrocytoma, Anaplastic Oligodendroglioma, Diffuse Astrocytoma, Diffuse Glioma, Glioblastoma, Metastatic Malignant Neoplasm in the Brain, Oligodendroglioma

Intervention / Treatment
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* Procedure: Microdialysis


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age >= 18 years Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0, 1 or 2 Diagnosis of the following, based on clinical and radiographic evidence: A diffuse glioma, or a prior diagnosis of a diffuse glioma. Diffuse gliomas include diffuse astrocytoma, anaplastic astrocytoma, glioblastoma, oligodendroglioma and anaplastic oligodendroglioma 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

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Basic Science (microdialysis)<br>Patients undergo microdialysis over 30 minutes during standard of care biopsy or resection. | Procedure: Microdialysis<br>* Undergo microdialysis<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of adverse events | Will be assessed by evaluating the proportion of patients who: (2) develop persistent adverse events deemed related (possibly, probably, definitely) to the insertion or use of microdialysate catheters. Attribution of neurologic deficit will typically be considered unlikely unless there is evidence of intra-operative intracranial hemorrhage that the surgeon deems to be attributable to use of the microdialysis catheter. Adverse events will be measured by Common Terminology Criteria for Adverse Events 5.0. | Up to 42 days | 
| Targeted metabolomics | Metabolites within each region of tumor to brain-adjacent-to tumor within a patient compared. Metabolites from patients without central nervous system malignancies averaged across the epileptic foci group and descriptively compared to the areas from patients with gliomas. | Up to 42 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Microdialysate D-2HG | Concentrations of D-2HG in microdialysate will be descriptively compared between patients with IDH mutated gliomas and those with IDH wildtype gliomas. | Up to 42 days | 
| Non-enhancing (FLAIR)- region metabolites | Metabolites of non-glioma, edema-associated FLAIR region of metastatic tumors descriptively compared to those within non-enhancing FLAIR gliomas. | Up to 42 days | 
| Necrotic core metabolites | The relative contribution of tumor cellularity versus blood-brain barrier disruption to metabolite production and loss determined by comparing metabolites within the necrotic tumor to those found within the enhancing tumor and brain -adjacent-to-tumor. | Up to 42 days | 
| Percentage of samples in which stable isotope labeled L-methionine- 13C5, 15N detected | Stable isotope detection and tracing performed. | Up to 42 days |