Fibroblast Activation Protein Inhibitor (FAPI)-Radioligand PET/CT in the Assessment of Nononcological Diseases: A Narrative Review

Abstract

This narrative review provides an overview of benign FAPI-PET/CT or PET/MRI findings and studies investigating molecular imaging in nononcological diseases. Although the current focus of 68GaGa-FAPI PET/CT is on oncologic indications, there is growing interest in the potential of FAPI PET/CT for nononcologic applications. Taking into account all-in-one, clinical, and preclinical studies, and the priorities of FAPI imaging over 2-18FFDG, the future direction of growing interest in the potential of FAPI tracer PET/CT as a promising technique in targeting fibroblast activation protein can be classified into some main fields for imaging and treatment monitoring. (1) Imaging of fibrotic disease, (2) cardiovascular imaging, (3) inflammatory and infectious diseases, (4) bone disease, (5) neuroimaging, and (6) organ transplantation imaging. The FAPI-radioligand shows promise as a targeted tracer for identifying and monitoring nononcological conditions, but current evidence is mainly based on small, heterogeneous retrospective analyses and case reports. Therefore, prospective studies are needed to reach reliable conclusions.