[Fibroblast activation protein inhibitor PET for monitoring fibrotic diseases].

Fibroblast activation protein inhibitor (FAPI) PET was initially developed for cancer diagnostics; however, studies suggest that FAPI PET is a promising modality in various fibrotic diseases, including interstitial lung disease, fibrotic myocardial diseases, and rheumatic diseases such as rheumatoid arthritis, IgG4-related disease, and systemic scleroderma. There are limited studies on the subject, but this review finds that FAPI PET can accurately and specifically visualise active fibrosis and holds potential for monitoring treatment response and differentiation between inflammation and fibrosis.