Chantal A M Bouman1,2, Noortje van Herwaarden2,3, Annelies B Blanken4,5, Conny J Van der Laken4, Martin Gotthardt6, Wim J G Oyen6,7,8, Alfons A den Broeder2,9, Aatke van der Maas2, Cornelia H van den Ende2,9. 1. Department of Rheumatology, Rijnstate Hospital, Arnhem. 2. Department of Rheumatology, Sint Maartenskliniek. 3. Department of Farmacology-Toxicology, Radboudumc, Nijmegen. 4. Department of Rheumatology, Amsterdam UMC-Location VU Medical Center. 5. Department of Rheumatology, Reade, Amsterdam. 6. Department of Nuclear Medicine, Radboudumc, Nijmegen, The Netherlands. 7. Department of Nuclear Medicine, Humanitas University and Clinical and Research Center, Milan, Italy. 8. Department of Nuclear Medicine, Rijnstate Hospital, Arnhem. 9. Department of Rheumatology, Radboudumc, Nijmegen, The Netherlands.
Abstract
OBJECTIVES: To investigate the reliability and validity of fluorine-18 fluorodeoxyglucose (18F-FDG) PET-CT scanning (FDG-PET) in RA patients with low disease activity tapering TNF inhibitors (TNFis) and its predictive value for successful tapering or discontinuation. METHODS: Patients in the tapering arm of the Dose REduction Strategies of Subcutaneous TNFi study, a randomized controlled trial of TNFi tapering in RA, underwent FDG-PET before tapering (baseline) and after maximal tapering. A total of 48 joints per scan were scored both visually [FDG-avid joint (FAJ), yes/no] and quantitatively [maximal and mean standardized uptake values (SUVmax and SUVmean)]. Interobserver agreement was calculated in 10 patients at baseline. Quantitative and visual FDG-PET scores were investigated for (multilevel) association with clinical parameters both on a joint and patient level and for the predictive value at baseline and the change between baseline and maximal tapering (Δ) for successful tapering and discontinuation at 18 months. RESULTS: A total of 79 patients underwent FDG-PET. For performance of identification of FAJs on PET, Cohen's κ was 0.49 (range 0.35-0.63). For SUVmax and SUVmean, intraclass correlation coefficients were 0.80 (range 0.77-0.83) and 0.96 (0.9-1.0), respectively. On a joint level, swelling was significantly associated with SUVmax and SUVmean [B coefficients 1.0 (95% CI 0.73, 1.35) and 0.2 (0.08, 0.32), respectively]. On a patient level, only correlation with acute phase reactants was found. FDG-PET scores were not predictive of successful tapering or discontinuation. CONCLUSIONS: Quantitative FDG-PET arthritis scoring in RA patients with low disease activity is reliable and has some construct validity. However, no predictive values were found for FDG-PET parameters for successful tapering and/or discontinuation of TNFi.
OBJECTIVES: To investigate the reliability and validity of fluorine-18 fluorodeoxyglucose (18F-FDG) PET-CT scanning (FDG-PET) in RA patients with low disease activity tapering TNF inhibitors (TNFis) and its predictive value for successful tapering or discontinuation. METHODS: Patients in the tapering arm of the Dose REduction Strategies of Subcutaneous TNFi study, a randomized controlled trial of TNFi tapering in RA, underwent FDG-PET before tapering (baseline) and after maximal tapering. A total of 48 joints per scan were scored both visually [FDG-avid joint (FAJ), yes/no] and quantitatively [maximal and mean standardized uptake values (SUVmax and SUVmean)]. Interobserver agreement was calculated in 10 patients at baseline. Quantitative and visual FDG-PET scores were investigated for (multilevel) association with clinical parameters both on a joint and patient level and for the predictive value at baseline and the change between baseline and maximal tapering (Δ) for successful tapering and discontinuation at 18 months. RESULTS: A total of 79 patients underwent FDG-PET. For performance of identification of FAJs on PET, Cohen's κ was 0.49 (range 0.35-0.63). For SUVmax and SUVmean, intraclass correlation coefficients were 0.80 (range 0.77-0.83) and 0.96 (0.9-1.0), respectively. On a joint level, swelling was significantly associated with SUVmax and SUVmean [B coefficients 1.0 (95% CI 0.73, 1.35) and 0.2 (0.08, 0.32), respectively]. On a patient level, only correlation with acute phase reactants was found. FDG-PET scores were not predictive of successful tapering or discontinuation. CONCLUSIONS: Quantitative FDG-PET arthritis scoring in RA patients with low disease activity is reliable and has some construct validity. However, no predictive values were found for FDG-PET parameters for successful tapering and/or discontinuation of TNFi.
Authors: Evy Ulijn; Alfons A den Broeder; Nadine Boers; Martin Gotthardt; Chantal A M Bouman; Robert Landewé; Nathan den Broeder; Noortje van Herwaarden Journal: Rheumatol Adv Pract Date: 2022-02-18
Authors: Matthijs S van der Leeuw; Marianne A Messelink; Janneke Tekstra; Ojay Medina; Jaap M van Laar; Saskia Haitjema; Floris Lafeber; Josien J Veris-van Dieren; Marlies C van der Goes; Alfons A den Broeder; Paco M J Welsing Journal: Arthritis Res Ther Date: 2022-03-23 Impact factor: 5.156