Avaliação de atividade da doença em pacientes com Arterite de Takayasu

Abstract

Objective: To analyze PET/CT performance in the assessment of disease activity in patients with Takayasu’s arteritis (TA), comparing PET/CT with clinical, laboratory and angiotomographic data. Methods: Diagnostic test study, 19 patients with TA according to ACR/1990 criteria, were evaluated for clinical, laboratorial (acute phase reagents) and imaging activity (angiotomography and PET/CT with 18F-FDG). Thickness and double ring images were considered vascular activity in the angiotomography and in the PET/CT three parameters were used to measure the capture values: visual scale, analysis of uptake intensity of the SUV (SUV ratio of a vascular region of interest/medium SUV hepatic) and SUVmax (maximum standardized uptake value). Results: 95% were female, mean (SD) age was 38 (8.3) years. Five (26.3%) clinically active patients, six (31.6%) with laboratory activity and eight (42.1%) in remission. Patients with clinical activity presented greater thickening of the aortic wall compared to patients with laboratory activity and remission (p = 0.02). Aortic wall thickening greater than 1.6 mm had a sensitivity of 59%, specificity of 75% (area below the ROC curve of 0.65, 95% CI of 0.56-0.88, p = 0.02) for predicting disease activity. Patients with double ring had a shorter duration of disease compared to patients without this vascular change [mean (SD) 7.5 (7.1) years vs 13.4 (4.3) years, p = 0.04). There was no difference in the medians of the values of the uptake intensity [median, min. and max., 1.93 (1.56-2.05) vs. 1.74 (1.3-2.06) vs. 1.97 (1.65-3.03), p = 0.18] and of the SUVmax [median, min. and max., 5.63 (4.65-7.3) vs. 5.23 (4.74-6.22) vs 6.1 (4.56-8.3), p = 0.57] of studied among clinical, laboratory and remission patients. There was no difference in the median values of the aortic SUVmax among patients with clinical and laboratorial activity and remission (p = 0.84). The median values of the SUVmax of the aortic branches were higher in the remission patients compared to those with clinical and laboratory activity (p = 0.01). There was no correlation between the medians of the wall thickness of the vessel at angiotomography and the intensity of uptake or SUVmax of the vessels most affected in the present study. Conclusions: Angiotomography showed good performance to identify aortic activity and PET/CT did not differentiate patients with disease activity from those in remission.