Correlation of 18F-FDG PET/CT assessments with disease activity and markers of inflammation in patients with early rheumatoid arthritis following the initiation of combination therapy with triple oral antirheumatic drugs.

PURPOSE: This study evaluated the potential of functional imaging to monitor disease activity and response to treatment with disease-modifying antirheumatic drugs (DMARD) in DMARD-naive patients with early rheumatoid arthritis (RA).
METHODS: The study involved 17 patients with active RA in whom combination therapy was initiated with methotrexate, sulfasalazine, hydroxychloroquine, and low-dose oral prednisolone. Clinical disease activity was assessed at screening, at baseline and after 2, 4, 8 and 12 weeks of therapy. (18)F-FDG PET/CT of all joints was performed at baseline and after 2 and 4 weeks of therapy.
RESULTS: (18)F-FDG maximum standardized uptake values showed a reduction of 22 ± 13 % in 76 % of patients from baseline to week 2 and a reduction of 29 ± 13 % in 81 % of patients from baseline to week 4. The percentage decrease in (18)F-FDG uptake from baseline to week 2 correlated with clinical outcome, as measured by the disease activity score (DAS-28) at week 12. In addition, changes in C-reactive protein levels and erythrocyte sedimentation rate were positively associated with changes shown by PET.
CONCLUSION: (18)F-FDG PET/CT findings after 2 and 4 weeks of triple combination oral DMARD therapy correlated with treatment efficacy and clinical outcome in patients with early RA. (18)F-FDG PET/CT may help predict the therapeutic response to novel drug treatments.