18F-4FN represents a novel PET agent for imaging inflammation. Acute inflammatory signaling through the TLR axis recruits neutrophils and macrophages to inflammatory sites. Both cells activate the production of high energy reactive oxygen species/reactive nitrogen species (RONS), setting off a cascade that can be leveraged to detect the presence of these inflammatory cells by molecular imaging. 18F-4FN is efficiently oxidized by high energy RONS, leading to retention and accumulation in human neutrophil-like cells in vitro, and at the sites of acute inflammation in vivo. Like 18F-FDG, 18F-4FN clears rapidly through the kidney at 1 hr following i.v. injection
Patient >/= 18 years of age.
Patients with histologic diagnosis of solid or liquid tumor treated by ICI with evidence of or clinical suspicion of irAE or patients with suspected inflammation.
Pregnant or lactating women: pregnant women are excluded from this study because the effects of [18F]4FN in pregnancy are not known. Urine or serum pregnancy test (female </= 60 years of age or childbearing potential) within 24 hours of the PET scan.
Subjects with contraindications to the use of [18F]4FN including confirmed allergy.
Patients with a body weight of 400 pounds or more, or a BMI which precludes their entry into the bore of the PET/CT scanner, because the hardware is not intended to support that weight.
Any additional medical condition, serious concurrent illness, or other extenuating circumstance that, in the opinion of the physician may significantly interfere with study compliance.