AVALIAÇÃO DE ATIVIDADE DE DOENÇA EM PACIENTES COM ARTERITE DE TAKAYASU ATRAVÉS DO 18F‐FLUORODEOXIGLICOSE (18F‐ FDG) TOMOGRAFIA POR EMISSÃO DE PÓSITRONS (PET/CT)

Takayasu's arteritis (TA) is a chronic inflammatory vasculitis with preferential involvement of the aorta, its major branches and pulmonary arteries. Activity assessment in TA is still a challenge. 18F-FDG PET/CT is a possible alternative for early detection and followup of these patients. Objective: Few studies have taken the advantage of 18F-FDG-PET/CT to personalize the patient evaluation and identify sites of more active disease in Takayasu Arteritis (TA) treated patients. This study aimed to evaluate the utility of F-FDG-PET/CT in identifying sites of active disease in patients under full treatment for TA. Methods: Patients under full treatment underwent whole-body F-FDG-PET/CT. Sites of increased F-FGD uptake were classified by a 3-scale visual analysis using the liver and left atrium uptake as reference. A quantitative analysis was also performed by measuring the maximum standardized uptake value (SUV) of the vascular wall of affected arteries. Disease activity using the NIH criteria was also evaluated. Results: Of 21 patients, 19 females and 2 males, mean age 40.5 (± 11.56) years, disease duration 8.3 (± 6.25) years. Fourteen participants (67%) were in inflammatory activity according to the criteria proposed by NIH. All patients were under treatment with immunosuppressive and/or immunobiological agents. Considering the quantitative analysis, the highest SUV value found was 19.2 in carotid artery and the lowest SUV value was 2.9 in subclavian artery. The mean maximum SUV did not differ between the clinically active and the inactive patients. In the visual analysis 95% of participants had at least one vascular site in inflammatory activity, with uptake ≥ 2 in relation to the liver and the left atrium. In both, aortic arch was most frequently involved. Conclusion: This study showed that the 18F-FDG-PET/CT is an effective imaging method to assess TA activity even in full treated patients.