Definition

A radioconjugate composed of FAPI-04, a quinoline-based fibroblast activation protein (FAP)-targeted tracer belonging to the group of FAP inhibitors (FAPi), conjugated with the bifunctional, macrocyclic chelating agent 1,4,7-triazacyclononane-N,N’,N”-triacetic acid (NOTA) and labeled with the radionuclide gallium Ga 68, with potential use as a tracer for FAP-expressing cancer-associated fibroblasts (CAFs) during positron emission tomography/computed tomography (PET/CT). Upon administration of gallium Ga 68-NOTA-FAPI-04, the FAPI-04 moiety targets and binds to FAP-expressing CAFs. Upon binding, FAP-expressing cells can be detected during PET/CT imaging. FAP, a cell surface protein, is overexpressed on CAFs in the tumor microenvironment (TME).