Multiparametric Metabolic and Hypoxic PET/MRI Imaging Substudy in Gliomas

This substudy will investigate a new imaging approach using positron emission tomography (PET) and two investigational drugs (\[18F\]FET and \[18F\]FMISO) to see if the imaging results will help with the placement of catheters for therapy delivery in 20 adult patients with malignant gliomas (MGs) who are participating in the UAB IRB approved main study, A Phase I/II Study of Pembrolizumab and M032 (NSC 733972), a Genetically Engineered HSV-1 Expressing IL-12, in Patients with Recurrent/Progressive and Newly Diagnosed Glioblastoma Multiforme, grade 3 or grade 4 astrocytoma, or Gliosarcoma (IRB 300007756 PI Markert). The PET and MR imaging results will be available to guide catheter placement within IRB 300007756 study-specific guidelines during Neurosurgery.

Inclusion Criteria: 1. Participants from IRB 300007756 2. 18 years of age or older at the time of enrollment 3. Able to undergo PET/MRI without anesthesia or sedation. Minimal sedation with ananxiolytic such as alprazolam used routinely for SOC MRI is allowed. 4. Females with childbearing potential must have a negative urine β-hCG test on the day of procedure or a serum hCG test within 48 hours prior to the administration of FET or FMISO. 5. ECOG performance score of 2 or better 6. Life expectancy greater than 12 weeks. Exclusion Criteria: 1. Any exclusions listed in IRB 300007756 2. Pregnancy or breast feeding 3. Inability to complete PET/MRI scans. 4. Significant renal dysfunction (estimated GFR \< 30 mL/min) 5. Any condition which may interfere with ability to participate in or complete all study-related activities as assessed by the study team 6. Unable to undergo MRI 7. Contraindication to gadolinium-based contrast