18F- FDG PET/CT joint assessment of early therapeutic response in rheumatoid arthritis patients treated with rituximab

Abstract

Background18F–FDG PET/CT has been proposed in the evaluation of the disease activity in rheumatoid arthritis (RA). The goals of this study were to evaluate the reproducibility of the technique, to compare metabolic parameters to clinical, biological and ultrasonographic parameters before and after treatment and to evaluate whether the early metabolic response was related to the outcome. 18F- FDG PET/CT of the hands, wrists and knees was obtained in 15 patients with anti-TNFα refractory RA, at baseline and 16 weeks after treatment with rituximab. The number of PET-positive joints (PET+ joints), the cumulative standard uptake value (cSUV) and the composite index (CI) were defined. The composite clinical index DAS28, CRP serum levels and the number of joints positive at ultrasonography (US+ joints) and the cumulative synovial thickness (CST) were also assessed at baseline and week 24.ResultsHigh interobserver agreement was observed, both at baseline and after treatment. The number of PET+ joints was not correlated with the number of joints tender or swollen. The 3 metabolic parameters were strongly correlated with US, CRP and DAS28 at baseline and with US and CRP (CSUV, CI) at week 16, but no longer with the DAS28 index. The metabolic response based on the change in the visual PET/CT joint analysis predicted the outcome with a high negative predictive value of 91%, with a 91% specificity, and an 86% accuracy.ConclusionsThese preliminary data suggest that 18F- FDG PET/CT is a reproducible and accurate tool for evaluating disease activity in refractory rheumatoid arthritis and its non-response to rituximab. The correlation obtained with US joint assessment gives relevance to objective diseased joints through imaging techniques.

Quantifying disease activity in rheumatoid arthritis with the TSPO PET ligand 18F-GE-180 and comparison with 18F-FDG and DCE-MRI

“…The 18 F-FDG sensitivity found in our study of 34% was lower. While the mean DAS28 score of 5.4 is representative for an RA patient population with moderate-to-high disease activity, the median CRP value found in our study was relatively low (3.0 (range: 1.5–24.5) mg/L) when compared to values found in the literature [6, 7, 48, 49]. It is possible that the low CRP levels in our study reflect a population with milder systemic inflammatory activity, which could in part explain the overall lower level of 18 F-FDG sensitivity.…”

Comparison of [18F] FDG-PET/MRI and Clinical Findings for Assessment of Suspected Lumbar Facet Joint Pain: A Prospective Study to Characterize Candidate Nonanatomic Imaging Biomarkers and Potential Impact on Management

“…While not well-studied in the facet joints, there is evidence that FDG activity can indicate an early response to systemic treatment in other inflammatory conditions, including inflammatory arthritis. 17,18 We found that high-grade perifacet findings were more common with gadolinium, supporting the assertion that further investigation with MR imaging protocols including gadolinium, rather than fat-suppressed T2 images alone, would be reasonable. The results also provide initial assessment of the approximate frequency and concordance of potential imaging biomarkers on multiplane fat-suppressed T2, fat-suppressed T1 gadolinium-enhanced, and FDG-PET images using a standardized protocol.…”

Prospective, simultaneous assessment of joint and vascular inflammation by PET/CT in tofacitinib-treated patients with rheumatoid arthritis: associations with vascular and bone status

“…► Joint and vascular inflammations as determined by PET/CT exerted multiple correlations with autoantibodies, systemic inflammation, lipids, carotid atherosclerosis and arterial stiffness. RMD Open RMD Open RMD Open predict clinical outcome in patients with RA undergoing combination conventional synthetic disease-modifying antirheumatic drug (csDMARD), 30 anti-tumour necrosis factor, 17 31-33 rituximab 34 or tocilizumab therapy. 35 In AS, the effects of statins could be monitored by PET/CT.…”