Use of 18F‐fluorodeoxyglucose Positron Emission Tomography to Monitor Disease Activity in Patients With Giant Cell Arteritis on Tocilizumab

Bibliographic Details
Title: Use of 18F‐fluorodeoxyglucose Positron Emission Tomography to Monitor Disease Activity in Patients With Giant Cell Arteritis on Tocilizumab
Authors: Kaitlin A. Quinn, Mark A. Ahlman, Peter C. Grayson
Source: ACR Open Rheumatology, Vol 7, Iss 2, Pp n/a-n/a (2025)
Publisher Information: Wiley, 2025.
Publication Year: 2025
Collection: LCC:Diseases of the musculoskeletal system
Subject Terms: Diseases of the musculoskeletal system, RC925-935
More Details: Objective The objective of this study was to assess the value of 18F‐fluorodeoxyglucose (FDG)– positron emission tomography (PET) scans to monitor disease activity in patients with giant cell arteritis (GCA) on tocilizumab. Methods Patients with GCA were recruited into a prospective cohort in which they underwent clinical, laboratory, and imaging assessments, including FDG‐PET. FDG‐PET scans were interpreted as active or inactive based on global impression by two independent readers. The PET Vascular Activity Score (PETVAS) was calculated to quantify arterial FDG uptake (scale 0–27). Vascular FDG‐PET findings were described in patients with GCA on tocilizumab for at least six months. For patients in established clinical remission, FDG‐PET findings were compared between those treated with tocilizumab versus glucocorticoid monotherapy. Results A total of 36 patients with GCA underwent FDG‐PET imaging on tocilizumab. Five patients had active clinical symptoms, and FDG‐PET scans were active in all cases (PETVAS range: 20–27). For the 31 patients in clinical remission on tocilizumab, FDG‐PET was active in 16 of these patients (52%) across a wide range of PETVAS (range 11–27). There were no associations between FDG‐PET activity during remission and historical clinical features or longitudinal outcomes, including relapse risk or angiographic progression of disease. PETVAS was significantly lower during clinical remission in patients treated with tocilizumab compared to an additional 12 patients treated with glucocorticoid monotherapy (PETVAS 18 vs 24; P = 0.02). Conclusion FDG‐PET has limited value to guide management decisions or inform prognosis when obtained during remission in patients with GCA on tocilizumab. Compared to glucocorticoid monotherapy, tocilizumab significantly reduces, but often does not eliminate, vascular inflammation in GCA.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2578-5745
Relation: https://doaj.org/toc/2578-5745
DOI: 10.1002/acr2.11797
Access URL: https://doaj.org/article/e22f54fdbc14442e911a98777b0def2e
Accession Number: edsdoj.22f54fdbc14442e911a98777b0def2e
Database: Directory of Open Access Journals
More Details
ISSN:25785745
DOI:10.1002/acr2.11797
Published in:ACR Open Rheumatology
Language:English