[18F]DASA-23 and PET Scan in Evaluating Pyruvate Kinase M2 Expression in Patients With Intracranial Tumors or Recurrent Glioblastoma and Healthy Volunteers

Inclusion Criteria: Age ≥18 years old. 2\. Adequate organ function (obtained within 14 days prior to PET scan \[Part 1, Part 2, and Part 3 ONLY\] or within 28 days prior to PET scan \[Part 4 ONLY\]) as evidenced by: 1. ANC ≥ 1.5 X 10\^9/L w/o myeloid growth factor support for 7 d preceding lab assessment 2. Hgb ≥ 9 g/dL (90 g/L); \< 9 g/dL (\< 90 g/L) is acceptable if Hgb is corrected to ≥ 9 g/dL (90 g/L) as by growth factor or transfusion prior to PET scan 3. Platelet count ≥ 100 X 10\^9/L w/o blood transfusions for 7 d preceding lab assessment 4. Bilirubin ≤ 1.5 X ULN except for pts w/ documented history of Gilbert's disease 5. ALT and AST ≤ 2.5 X ULN 6. Alkaline phosphatase (AP) ≤ 3 X ULN 7. Women of childbearing potential (WCBP): negative serum pregnancy test 3\. Ability to stand up and climb two steps with minimal assistance. 4\. Ability to understand and the willingness to sign a written informed consent document. 5\. (Part 2, intracranial tumor patients ONLY) (a) Radiographical or pathological evidence of newly-diagnosed intracranial tumor that is status-pre surgical resection, or (b) Radiographical or pathological evidence of progressive/recurrent intracranial tumor, (c) Question of pseudoprogression vs. true progression on most recent standard-of-care brain MRI, or (d) Evidence on the most recent standard-of-care brain MRI scan of intracranial metastasis/metastases in a patient with known extracranial primary cancer. 6\. (Part 3, GBM patients ONLY) Any patient with at least a 1cm3 contrast-enhancing lesion suspicious for GBM (either newly-diagnosed or 1st /2nd/ 3rd recurrence of GBM, molecular GBM, diffuse astrocytomas with molecular features of GBM, H3K27M midline gliomas, gliosarcomas, or any other WHO Grade IV glioma) on a standard-of-care (SOC) brain MRI scan. If the patient undergoes a biopsy or resection for GBM (either newly-diagnosed or 1st /2nd/ 3rd recurrence of GBM, molecular GBM, diffuse astrocytomas with molecular features of GBM, H3K27M midline gliomas, gliosarcomas, or any other WHO Grade IV glioma) then the remaining contrast-enhancing lesion is at least 1cm3 in size on the post-operative scan. 7\. (Part 3, GBM patients ONLY) Life expectancy of ≥ 6 months. Exclusion Criteria: 1. Known allergy to adhesive tapes or other skin adhesives used in medical care 2. Subjects with the following co-morbid disease or incurrent illness: 1. With known cirrhosis diagnosed with Child-Pugh Class A or higher liver disease. 2. Severe/uncontrolled inter-current illness within the previous 28 days prior to PET scan 3. Patients who have implantable devices that are contra-indicated for MRI 4. Bleeding disorder 5. Any other significant co-morbid conditions that in the opinion of the Investigator would impair study participation or cooperation. 6. (Healthy volunteers ONLY - Part 1 and Part 4) prior or current malignancy 7. (Healthy volunteers ONLY - Part 1 and Part 4) known kidney disease 3. Pregnant or nursing participants 4. History of allergic reactions to gadolinium-based MRI contrast agent 5. (Part 2, intracranial tumor patients ONLY) Other chemotherapy (besides what is being used to treat the intracranial tumor) 6. (Part 3, GBM patients ONLY) Has already begun therapy, prior to the first of two \[18F\]DASA-23 PET/MRI scans.