LAUSR

OBJECTIVE To investigate the ability of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) to predict new lesions in Takayasu arteritis (TA). METHODS Eighty-two Chinese patients with newly diagnosed TA were recruited. Their clinical characteristics, serum biomarkers, and imaging results were recorded at baseline and every visit. They were followed up for at least 2 years. New angiographic lesions were evaluated by magnetic resonance angiography. Baseline PET vascular activity scores (PETVAS) for predicting new lesions were evaluated. RESULTS At baseline, a moderate correlation was observed between PETVAS and erythrocyte sedimentation rate (ESR) (r = 0.74, p< 0.01) and C-reactive protein (CRP) level (r = 0.69, p< 0.01). Overall, 18 (22%) patients showed new lesions on imaging during a median follow-up time of 36 months. The median time to the first occurrence of new lesions was 18 months. Compared with patients without new lesions, the patients with new lesions included more female patients (67.2% vs 94.4%, p= 0.03), patients with higher ESR values (20 vs 49, p= 0.02), and patients with active disease (62.5% vs 94.4%, p< 0.01). Multivariate Cox regression analysis revealed PETVAS was an independent risk factor for new angiographic lesions (PETVAS ≥ 8, HR = 7.56; 95% CI, 2.20-26.01, p< 0.01) with adjustment of age, sex, chest pain, ESR, and Physician Global Assessment (PGA). Furthermore, patients with PETVAS ≥ 8 at baseline were more likely to experience adverse events including arterial ischaemic events during the follow-up. CONCLUSION PETVAS showed good performance in predicting new lesions in TA.