[68 Ga]Ga-FAPI-04 PET/CT may be a predictor for early treatment response in rheumatoid arthritis

Abstract

Abstract Background The identification of biomarkers predicting the treatment response of rheumatoid arthritis (RA) is important. [68 Ga]Ga-FAPI-04 showed markedly increased uptake in the joints of patients with RA. The purpose of this study is to investigate whether [68 Ga]Ga-FAPI-04 PET/CT can be a predictor of treatment response in RA. Results Nineteen patients diagnosed with RA in the prospective cohort study were finally enrolled. Both total synovitis uptake (TSU) and metabolic synovitis volume (MSV) in [68 Ga]Ga-FAPI-04 and [18F]FDG PET/CT of the responders were significantly higher than those in non-responders according to Clinical Disease Activity Index (CDAI) and Simplified Disease Activity Index (SDAI) response criteria at 3-months’ follow-up (P cutoff values in [68 Ga]Ga-FAPI-04 PET/CT successfully discriminated CDAI and SDAI responders and non-responders at 3-months’ follow-up. Conclusion [68 Ga]Ga-FAPI-04 uptake at baseline were significantly higher in early responders than those in non-responders. Trial registration ClinicalTrials. NCT04514614. Registered 13 August 2020, https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S000A4PN&selectaction=Edit&uid=U0001JRW&ts=2&cx=-x9t7cp

Keywords

• Rheumatoid arthritis
• [68 Ga]Ga-FAPI-04
• [18F]FDG
• PET/CT
• Treatment response