[18F]-FAC

[18F]-FAC (1-(2-deoxy-2-[18F]fluoro-β-D-arabinofuranosyl)cytosine) is a radiolabeled nucleoside analog used as a positron emission tomography (PET) imaging tracer. It is a 2'-deoxycytidine analog that serves as a substrate for the enzyme deoxycytidine kinase (dCK), which is the rate-limiting step in the deoxyribonucleoside salvage pathway. Because dCK is also responsible for the activation of several important nucleoside analog prodrugs, such as gemcitabine, cytarabine, and cladribine, [18F]-FAC PET imaging can be used to non-invasively measure dCK activity in vivo. This allows for the prediction of therapeutic response to these drugs, identification of patients with dCK-deficient resistant tumors, and monitoring of immune responses, as dCK is highly expressed in proliferating and activated lymphocytes. The tracer has been evaluated in clinical trials for various cancers and immunological conditions to optimize treatment regimens and reduce unnecessary side effects.

Other names

1-(2-deoxy-2-[18F]fluoro-beta-D-arabinofuranosyl)cytosine2'-deoxy-2'-[18F]fluoro-beta-D-arabinofuranosylcytosine[18F]fluoro-arabinofuranosylcytosine