ACR Meeting Abstracts

ACR Meeting Abstracts

Abstract Number: 0233

Comparisons of Ga-FAPI and FDG PET/CT with X-ray Imaging in the Assessment of Rheumatoid Arthritis Patients

Jiana Chen1, Dan Yang1, Ziyue Zhou2, Yaping luo3 and Huaxia Yang1, 1Department of Rheumatology and Clinical Immunology, National Clinical Research Center for Dermatologic and Immunologic Diseases, the Ministry of Education Key Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 2Department of Rheumatology and Clinical Immunology,  Peking Union Medical College Hospital, Beijing, China, 3Department of Nuclear Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College Hospital, No.1 Shuaifuyuan Wangfujing, Dongcheng District, Beijing, 100730, China., Beijing, China

Meeting: ACR Convergence 2024

Keywords:

Session Information

Date: Saturday, November 16, 2024

Title: Imaging of Rheumatic Diseases Poster I: Inflammatory Arthritis

Session Type: Poster Session A

Session Time: 10:30AM-12:30PM

Background/Purpose:  The imaging techniques for assessing rheumatoid arthritis (RA), including x-ray, musculoskeletal ultrasound, MRI and positron emission tomography/computed tomography (PET/CT). Fibroblast-like synoviocyte cells, which are involved in inflammation of the articular cartilage and bone, overexpress fibroblast activation protein (FAP), which is a feature that could be leveraged to improve imaging assessment of disease. The purpose of our study was to determine the imaging techniques of gallium 68 (68Ga)-labeled FAP inhibitor (FAPI) and fluorine 18 (18F) fluorodeoxyglucose (FDG) imaging, compared with traditional X-ray imaging in assessing disease activity and treatment response in patients with RA.

Methods: We prospectively enrolled 17 participants diagnosed with RA including 14 females and 3 males (52.9±10.5 yr, range 25-65 yr). All patients were evaluated for disease activity through clinical and laboratory assessment and underwent X-ray and dual-tracer PET/CT ([68Ga]Ga-FAPI-04 PET/CT and [18F]FDG PET/CT) imaging, with 6-months’ follow-up to monitor disease progression. Bland-Altman analysis was performed to assess the agreement in X-ray and dual-tracer PET/CT. Additionally, we explored correlations between disease activity values (including ESR, tender or swollen joint count, VAS of pain, PGA, EGA, CDAI, SDAI, DAS28-ESR, DAS28-CRP) and parameters of imaging findings (including Stage and Larsen score in X-ray, PJC, PAI, TSU, MSV and SUVmax in dual-tracer PET/CT).

Results: The Bland-Altman analysis indicated a high level of agreement between X-ray and PET-CT in evaluating joint conditions in RA patients, with mean differences within acceptable limits and narrow 95% limits of agreement. PJCFAPI, PAIFAPI, PJCFDG, and PAIFDG at baseline showed a stronger positive correlation with CRP, CDAI, SDAI, DAS28-ESR, and DAS28-CRP, while no statistical differences were observed between X-ray and clinical characteristics of RA patients. Additionally, PET/CT rather than X-ray parameters could significantly predict treatment response.

Conclusion: [68Ga]Ga-FAPI-04 PET/CT and [18F]FDG PET/CT were superior to traditional X-ray in evaluating the disease activity of RA and predicting treatment response.

Supporting image 1

Table 1. Correlation test of baseline clinical characteristics and imaging findings.

Supporting image 2

Figure 1. Receiver operating characteristic analysis curves of baseline characteristics for predicting 6-months’ CDAI response.

Supporting image 3

Figure 2. Receiver operating characteristic analysis curves of baseline characteristics for predicting 6-months’ SDAI response.

Disclosures: J. Chen: None; D. Yang: None; Z. Zhou: None; Y. luo: None; H. Yang: None.

To cite this abstract in AMA style:

Chen J, Yang D, Zhou Z, luo Y, Yang H. Comparisons of Ga-FAPI and FDG PET/CT with X-ray Imaging in the Assessment of Rheumatoid Arthritis Patients [abstract]. Arthritis Rheumatol. 2024; 76 (suppl 9). https://acrabstracts.org/abstract/comparisons-of-ga-fapi-and-fdg-pet-ct-with-x-ray-imaging-in-the-assessment-of-rheumatoid-arthritis-patients/. Accessed .

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