The Role of Fibroblast Activation Protein Ligands in Oncologic PET Imaging.

Fibroblast activation protein inhibitor emerges as a novel and highly promising agent for diagnostic and possibly theranostic application in various malignant and non-malignant diseases. FAPI impresses with its selective expression in several pathologies, ligand induced internalization, and presence in a large variety of malignancies. Current studies indicate that FAPI is equal or even superior to the current standard oncological tracer fluorodeoxyglucose in several oncological diseases. It seems to present lower background activity, stronger uptake in tumorous lesions and thus sharper contrasts. For improved comprehension of fibroblast activation, protein expression and clinicopathologic conditions, further studies are of essence.