Carbon C 11 PBR-28 PET/MRI in Measuring Inflammation in Patients with Brain Tumors Undergoing Treatment with Chemoradiation or Immunotherapy

Inclusion Criteria

• Participants must have evidence of metastatic cancer to the brain for cohort A or histologically confirmed glioblastoma (GBM) for cohorts B and C
• Those with GBM but suspected to have pseudoprogression at any time after completion of chemoradiation can enroll in cohort C
• Participants must have measurable brain disease, defined as at least one lesion that is 10 mm in diameter
• Eastern Cooperative Oncology Group (ECOG) performance status =< 2 (Karnofsky >= 60%)
• Life expectancy of greater than 3 months
• Leukocytes >= 3,000/mcL
• Absolute neutrophil count >= 1,500/mcL
• Platelets >= 100,000/mcL
• Total bilirubin within normal institutional limits
• Aspartate aminotransferase (AST) (serum glutamic-oxaloacetic transaminase [SGOT]) / alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase [SGPT]) =< 2.5 x institutional upper limit of normal
• Creatinine within normal institutional limits OR creatinine clearance >= 55 mL/min/1.73 m^2 for participants with creatinine levels above institutional normal
• For cohort A, only patients with metastatic cancer to the brain for whom their treating physician has planned to give immunotherapy as monotherapy are eligible for this study; this can be in the setting of a clinical trial or not
• For cohort B, only patients with GBM for whom their treating physician has planned to give immunotherapy are eligible for this study; this can be in the setting of a clinical trial or not
• For cohort C, patients with GBM who have completed standard temozolomide + radiation and have suspected pseudoprogression can enroll; there is no time frame from completion of chemoradiation as pseudoprogression is increasingly recognized at later time points
• Patient must be able to undergo MRI and PET scans
• Patient must be maintained on a stable corticosteroid regimen for 5 days prior to each MR-PET scan
• High or mixed affinity binders (alanine [Ala]/Ala or Ala/threonine [Thr]) based on genotyping result from PBR affinity test; this blood test will be performed as part of the screening process after consent has been obtained
• Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation; should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately; radiopharmaceutical agents are known to be teratogenic
• Ability to understand and the willingness to sign a written informed consent document

Exclusion Criteria

• History of allergic reactions attributed to compounds of similar chemical or biologic composition to PBR
• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements
• Pregnant women are excluded from this study; breastfeeding should be discontinued
• Human immunodeficiency virus (HIV)-positive participants are excluded
• Patients who are not suitable to undergo MRI or PET or use gadolinium contrast due to: * Claustrophobia * Presence of metallic objects or implanted medical devices in body (i.e. cardiac pacemaker, aneurysm clips, surgical clips, prostheses, artificial hearts, valves with steel parts, metal fragments, shrapnel, tattoos near the eye, or steel implants); the craniotomy patients will all have titanium but this is MRI compatible * Sickle cell disease * Renal failure * Reduced renal function, as determined by creatinine clearance < 30 mL/min based on a serum creatinine level obtained within 28 days prior to registration