FAPI PET/CT Imaging-An Updated Review

Despite revolutionizing the field of oncological imaging, Positron Emission Tomography (PET) with [F-18]Fluorodeoxyglucose (FDG) as its workhorse is limited by a lack of specificity and low sensitivity in certain tumor subtypes. Fibroblast activation protein (FAP), a type II transmembrane glycoprotein, is expressed by cancer-associated fibroblasts (CAFs) that form a major component of the tumor stroma. FAP holds the promise to be a pan-cancer target, owing to its selective over-expression in a vast majority of neoplasms, particularly epithelial cancers. Several radiolabeled FAP inhibitors (FAPI) have been developed for molecular imaging and potential theranostic applications. Preliminary data on FAPI PET/CT remains encouraging, with extensive multi-disciplinary clinical research currently underway. This review summarizes the existing literature on FAPI PET/CT imaging with an emphasis on diagnostic applications, comparison with FDG, pitfalls, and future directions.

Automated summary

Despite limitations in specificity and sensitivity, Positron Emission Tomography (PET) using [F-18]Fluorodeoxyglucose (FDG) has revolutionized oncological imaging. Fibroblast activation protein (FAP), expressed by cancer-associated fibroblasts (CAFs), shows promise as a pan-cancer target. Radiolabeled FAP inhibitors (FAPI) have been developed for molecular imaging and theranostic applications, with encouraging preliminary data on FAPI PET/CT and ongoing clinical research. This review summarizes the literature on FAPI PET/CT imaging, focusing on diagnostic applications, comparison with FDG, pitfalls, and future directions.