Vol.:(0123456789) 1 3 Rheumatology International https://doi.org/10.1007/s00296-020-04551-2 IMAGING A retrospective cohort study to assess PET‑CT fndings and clinical outcomes in Takayasu arteritis: does 18F‑fuorodeoxyglucose uptake in arteries predict relapses? Anna Larissa Faria Janes 1  · Míriam Fang Castro 1  · Anne Elizabeth Diniz Arraes 1  · Bruna Savioli 1  · Emília Inoue Sato 1  · Alexandre W. S. de Souza 1 Received: 19 December 2019 / Accepted: 11 March 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract The objective of this study is to investigate the use of PET-CT scan with 18F-fuorodeoxyglucose (18F-FDG) as a method to predict outcomes in patients with Takayasu arteritis (TAK), as well as to analyze associations between 18F-FDG PET-CT fndings with disease relapses, sustained remission, new angiographic lesions, ischemic events, and changes in therapy for TAK. At baseline assessment, 36 TAK patients underwent 18F-FDG PET-CT scan and maximal standardized uptake value (SUVmax) in arteries ≥ 1.3 was predictive for clinical disease activity. Thirty-two TAK patients were then followed-up for a median 83.5 months. Twenty-three (71.9%) patients developed clinical relapses and new arterial lesions were observed in 14 (43.8%) cases. Disease relapses [85.0% vs. 50.0%, p = 0.049; odds ratio (OR): 5.667; 95% confdence interval (95 CI): 1.067–30.085] and the need for changing immunosuppressive therapy (85.0% vs. 41.7%, p = 0.018; OR: 7.933; 95CI: 1.478–42.581) were more frequently found in patients with SUVmax ≥ 1.3 at baseline compared with those presenting SUVmax < 1.3. No associations were found between SUVmax ≥ or < 1.3 in large arteries at baseline and the development of ischemic events, sustained remission or new angiographic lesions. In multivariate analysis, associations between baseline SUVmax ≥ 1.3 and disease relapses were not independent (hazard ratio: 1.07; 95 CI 0.39–2.92; p = 0.892). In conclusion, arterial SUVmax is marginally associated with disease relapses and with the need to change therapy in TAK. 18F-FDG uptake in large arteries is not associated with the development of new arterial lesions in TAK. Keywords Takayasu arteritis · Positron-emission tomography · Recurrence · Immunosuppression · Positron-emission tomography computed tomography Introduction Takayasu arteritis (TAK) is a large-vessel systemic vasculitis that afects the aorta, its primary branches and pulmonary arteries. The infammatory infltration in arterial walls of TAK patients leads to concentric thickening and may result in irreversible damage with stenosis, occlusion, dilation or aneurysm formation [1, 2]. TAK has a pattern of arterial involvement that more frequently afects left subclavian arteries, abdominal arteries or the carotid and subclavian arteries at both sides when compared to giant cell arteritis [3]. The defnition of disease remission in TAK is difcult in clinical practice, since arterial infammation often persists in TAK patients who are thought to present quiescent disease, as shown in artery specimens from TAK patients who under- went by-pass vascular surgery [4–6]. In addition, when TAK patients are followed-up longitudinally, progressive arterial lesions are found in 53–71% even in the absence of overt signs and symptoms of active disease [6–8]. Disease activity in TAK may be assessed by diferent tools in clinical practice and in diferent studies including the Kerr’s criteria, the Birmingham Vasculitis Activity Score (BVAS), the Disease Extent Index in Takayasu Arte- ritis (DEI-TAK), and more recently by the Indian Takayasu Clinical Activity Score (ITAS2010) [ 6, 9–12]. Serial non-invasive imaging studies using magnetic resonance Rheumatology INTERNATIONAL This study was published as congress abstract in Refs. [47, 48]. * Alexandre W. S. de Souza alexandre_wagner@uol.com.br 1 Rheumatology Division, Department of Medicine, Escola Paulista de Medicina, Universidade Federal de São Paulo, Rua Botucatu 740 3° andar, São Paulo, SP 04023-900, Brazil