Definition

A radioconjugate composed of FAPI-XT117, a fibroblast activation protein inhibitor (FAPi), labeled with the radionuclides gallium Ga 68 and copper Cu 64, 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/copper Cu 64-labeled FAPI-XT117, the FAPI-XT117 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).