Low accrual

In the current study, advanced positron emission tomography/computed tomography (PET/CT) and positron emission tomography/magnetic resonance (PET/MR) imaging methods will be used to validate the hypothesis that participants receiving immune checkpoint blockade (ICB) therapy, who ultimately achieve clinical benefit, will show an increase, or "FLARE", in tumor FLT and/or FDG uptake from baseline, as seen after cycle#1 of treatment, and that after 2 cycles of treatment responders will have a decline in FLT and FDG uptake, in comparison to the participants classified as "non-responders".

Inclusion Criteria:

• Patients must have histologically or cytologically confirmed diagnosis of cancer.
• Patients who are planned to receive checkpoint blockade therapy, per referring oncologist.
• Life expectancy ≥ 6 months and < 5 years.
• Disease that is measurable per RECIST 1.1.
• Age ≥18 years.
• Ability and willingness to provide informed consent
• Women of child-bearing potential must have a negative urinary or serum pregnancy test within 7 days of each imaging time point.

Exclusion Criteria:

• Patient receiving other investigational radiotracers within 14 days prior to FLT and FDG imaging time points.
• Patients receiving ICB in combination with chemotherapy.
• Immunosuppressive therapy including systemic corticosteroids except for maintenance dosing for adrenal insufficiency. Patients requiring immunosuppressive therapy during the study will no longer be eligible.
• Known additional malignancy that is progressing or requires active treatment with the exceptions of basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or in situ cervical cancer that has undergone potentially curative therapy.
• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, autoimmune diseases, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements
• Patients with a pacemaker, stainless steel aneurysm clip or any other magnetic resonance (MR) contraindicated implant or foreign body would warrant exclusion from this study. Pacemakers may be reprogrammed or turned off by the strong MRI magnetic field. Radio-frequency (RF) fields in MR can also cause severe heating of pacemaker lead tips. Steel aneurysm clips are prone to torque in the strong MR field which can displace the clips and may damage the vessel, resulting in hemorrhage, and/or death.
• Pregnant women are excluded from this study

Data may be shared with other researchers. The researchers may be doing research at Washington University, at other research centers and institutions, or industry sponsors of research. Data may also be shared with large data repositories. The researchers may be doing research in areas similar to this research or in other unrelated areas.

Beginning 3 months and ending 10 years following article publication.

Proposals should be submitted directly to rwahl@wustl.edu.