68 Ga-FAPI PET/CT for Rheumatoid Arthritis: A Prospective Study

作者：Yaping Luo, Qingqing Pan, Ziyue Zhou, Min Li, Yanping Wei, Jiang Xu, Huaxia Yang, Fang Li · 发表于：Radiology · 年份：2023 · DOI：10.1148/radiol.222052 · 被引用次数：82 · 研究领域：Peptidase Inhibition and Analysis、Radiopharmaceutical Chemistry and Applications、Protease and Inhibitor Mechanisms

Background In rheumatoid arthritis (RA), fibroblast-like synoviocyte cells, which are involved in inflammation of the articular cartilage and bone, overexpress fibroblast activation protein (FAP). This is a feature that could be leveraged to improve imaging assessment of disease. Purpose To determine the performance of gallium 68 (68Ga)-labeled FAP inhibitor (FAPI) in assessing joint disease activity of RA and to compare with fluorine 18 (18F) fluorodeoxyglucose (FDG) imaging. Materials and Methods Twenty participants with RA (15 women; mean age, 55 years ± 10 [SD]) were prospectively enrolled from September 2020 to December 2021 and underwent clinical and laboratory assessment of disease activity and dual-tracer PET/CT (68Ga-FAPI and 18F-FDG) imaging. Imaging-derived variables of PET joint count (the number of joints positive for RA at PET) and PET articular index (a sum of the points of the joints using a three-point scale) were correlated to clinical and laboratory variables of disease activity. Results The combined output of both PET/CT techniques helped detect 244 affected joints, all of which showed positive results at 68Ga-FAPI PET/CT. However, fifteen of 244 (6.1%) FAPI-avid joints in six of 20 (30%) participants were not detected at 18F-FDG PET/CT. The maximum standardized uptake value of the most affected joint in each participant was higher in 68Ga-FAPI than in 18F-FDG PET/CT (9.54 ± 4.92 vs 5.85 ± 2.81, respectively; P = .001). The maximum standardized uptake valu...