Assessment of Takayasu arteritis in routine practice with PETVAS, an 18F-FDG PET quantitative scoring tool

Abstract

The aim of this study was to evaluate the value of PET Vascular Activity Score (PETVAS) during the follow-up of patients with Takayasu arteritis. Takayasu arteritis patients who underwent 18F-Fluorodeoxyglucose (FDG) PET imaging were evaluated retrospectively. In 8 patients both 1 and 2-hour imagings were also performed prospectively. For PETVAS, 9 arterial areas were scored between 0-3 according to the FDG uptake. Forty-six images of 34 patients were evaluated. PETVAS was higher in patients with clinically active disease (p=0.03) and in C-reactive protein (CRP) elevated group among clinically inactive patients (p=0.0015). PETVAS correlated with CRP (p=0.003, r=0.53) and erythrocyte sedimentation rate (p=0.005, r=0.41), whereas age, disease duration, immunosuppressive and glucocorticoid (GC) treatments were not associated with PETVAS. First vs 2nd-hour PETVAS was similar in patients who had both 1st and 2nd hour PET scans (p=0.67). We observed higher PETVAS in patients with active disease and elevated acute phase reactants. Although scores in our study (performed at one-hour) were lower compared to the original PETVAS study performed at two hours, PETVAS seems to be a reliable tool to quantify FDG PET scores in routine practice.