Time-course of tophus resolution on Dual-energy CT and ultrasound after 24months of a treat-to-target strategy: Results from GOUT-DECTUS study

• Published in: Joint, bone, spine : revue du rhumatisme Vol. 92; no. 4; p. 105892
• Main Authors: Pascart, Tristan, Richette, Pascal, Bousson, Valérie, Ottaviani, Sébastien, Ea, Hang-Korng, Lioté, Frédéric, Latourte, Augustin, Bardin, Thomas, Ora, Jérémy, Pacaud, Aurore, Vandecandelaere, Marie, Luraschi, Hélène, Jauffret, Charlotte, Laurent, Victor, Boissel, Mathilde, Norberciak, Laurène, Legrand, Julie, Lefevre, Guillaume, Ducoulombier, Vincent, Budzik, Jean-François
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.07.2025
• Subjects: Aged; Dual-energy computed tomography; Female; Gout; Gout - blood; Gout - diagnostic imaging; Gout - drug therapy; Gout Suppressants - therapeutic use; Humans; Longitudinal Studies; Male; Middle Aged; Monosodium urate; Pilot Projects; Prospective Studies; Time Factors; Tomography, X-Ray Computed - methods; Treatment Outcome; Ultrasonography - methods; Ultrasound; Uric Acid - blood; Monosodium urate; Dual-energy computed tomography; Ultrasound; Gout
• ISSN: 1297-319X; 1778-7254
• DOI: 10.1016/j.jbspin.2025.105892

•Complete crystal dissolution of tophus core is observed in dual-energy CT after 24months of treat-to-target while ultrasound tophi can persist.•Kinetics of crystal dissolution observed with dual-energy CT are more rapid and often complete by month 12 of treat-to-target therapy, while those of the decrease of tophus volume measured with ultrasound are slower.•Measurement of the individual volumes of tophi with ultrasound is unreliable. The main objective of the study was to evaluate the kinetics of tophus volume measured with dual-energy CT (DECT) and ultrasound (US) in patients with gout during their first 24months of treat-to-target (T2T) urate-lowering therapy. This was a prospective, multicenter, 24-month longitudinal pilot study including ULT-naïve patients with gout and US tophi. Clinical visits, and DECT and US scans of the knees and feet were performed at baseline, 6, 12 and 24months. The largest tophus identified by US was chosen as the index tophus. The primary outcome was the change in the absolute volume and relative change from baseline of the tophus index volume measured with US and with DECT at all timepoints, with their correlation assessed by the Spearman correlation coefficient (ρ). A total of 55 patients (63.1 (12.3) years old, predominantly male (47/55 [85.5%]), with baseline serum urate levels of 8.73 mg/dL [7.93; 9.52] were included. Index tophus volume measured with US changed from median [inter-quartile range] 0.61 cm3 [0.30; 1.20] at baseline to 0.07 cm3 [0; 0.50] at month 24, and with DECT from 0.1 cm3 [0; 0.63] at baseline to 0 cm3 [0; 0] at month 24. Relative changes in index tophus volume measured with US and DECT were respectively −56% [−90; 0] and −96% [−100; −34] at M6, −84% [−100; −13] and −100% [−100; −89] at M12, and −96% [−100; −72] and −100% [−100; −100] at M24. The correlation for relative tophus volume change was weak at month 6 (ρ=0.39 [0.01; 0.74]) and moderate at months 12 (ρ=0.43 [−0.14; 0.82]) and 24 (ρ=0.42 [−0.01; 0.73]). Complete tophus resolution is obtained at 24months of T2T in DECT but not in US, which provided a greater variability of volumetric assessments throughout follow-up.