18F-Fluorodeoxyglucose Positron Emission Tomography Imaging Assessment Within a Randomized Controlled Trial in Giant Cell Arteritis

Quinn KA, Tan S, Verdijk P, Okonkwo L, Samson M, Blockmans D, Makhzoum JP, Cid MC, Henes J, Schönau V, Ahlman MA, Grayson PC (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Arthritis and Rheumatology Wiley

DOI: 10.1002/art.70166

Abstract

Objective: To compare fluorodeoxyglucose (FDG)–positron emission tomography (PET) imaging to clinical- and laboratory-based assessments of disease activity in a randomized controlled trial (RCT) in giant cell arteritis (GCA). Methods: Patients with new-onset or relapsing GCA were randomized to guselkumab or placebo plus tapered glucocorticoids in an international, multicenter RCT. FDG-PET was performed at the baseline visit before randomization and repeated at disease flare or the week-52 visit (clinical remission off glucocorticoids). FDG-PET scans were interpreted as active or inactive by two readers, and the PET Vascular Activity Score was calculated to quantify arterial FDG uptake. FDG-PET findings were compared to clinical assessment, acute phase reactants, and glucocorticoid use at each visit. Results: Baseline FDG-PET scans were interpreted as active vasculitis in 28 (55%) of 51 patients. FDG-PET activity at enrollment was not associated with clinical symptoms, acute phase reactants, or risk of flare. Younger age (70 vs 76 years; P = 0.03) and female sex (89% vs 48%, P < 0.01) were significantly associated with increased FDG-PET activity. There were no differences in prior glucocorticoid dose (median 780 mg) or duration (median 23 days) between patients with baseline active versus inactive FDG-PET scans. FDG-PET scans were active in 17 of 21 (81%) patients during clinical flare and in 14 of 20 (70%) patients at week 52. Subsets of patients had persistently active (n = 21) or inactive (n = 9) PET scans at all time points, independent of clinical assessment. Conclusion: Vascular FDG-PET activity may be discordant with clinical assessment, particularly in subsets of patients with GCA. Imaging-based outcome measures should remain exploratory in future therapeutic trials.

Authors with CRIS profile

Verena Schönau Department of Medicine 3 – Rheumatology and Immunology

Involved external institutions

National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) US United States (USA) (US) Johnson & Johnson Services, Inc. US United States (USA) (US) Centre hospitalier universitaire (CHU) de Dijon Bourgogne FR France (FR) University Hospital Leuven (UZ) / Universitaire ziekenhuizen Leuven BE Belgium (BE) Université de Montréal CA Canada (CA) Universitat de Barcelona (UB) / University of Barcelona ES Spain (ES) Universitätsklinikum Tübingen DE Germany (DE) Augusta University US United States (USA) (US)

How to cite

APA:

Quinn, K.A., Tan, S., Verdijk, P., Okonkwo, L., Samson, M., Blockmans, D.,... Grayson, P.C. (2026). 18F-Fluorodeoxyglucose Positron Emission Tomography Imaging Assessment Within a Randomized Controlled Trial in Giant Cell Arteritis. Arthritis and Rheumatology. https://doi.org/10.1002/art.70166

MLA:

Quinn, Kaitlin A., et al. "18F-Fluorodeoxyglucose Positron Emission Tomography Imaging Assessment Within a Randomized Controlled Trial in Giant Cell Arteritis." Arthritis and Rheumatology (2026).

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