Disease activity and vascular involvement in retroperitoneal fibrosis: first experience with fully integrated 18F-fluorodeoxy-glucose positron emission tomography/magnetic resonance imaging compared to clinical and laboratory parameters

作者：Thuermel K^*; Einspieler I; Wolfram S; Moog P; Meier R; Schwaiger M; Heemann U

来源：Clinical and Experimental Rheumatology, 2017, 35(1): S146-S154.

• retroperitoneal fibrosis
• large-vessel vasculitis
• hybrid [18F]-FDG PET/MRI

Objective. The aim of this study was to evaluate the value of fully integrated [18F]FDG PET/MRI in the assessment of retroperitoneal fibrosis with regard to disease activity, extent and vascular involvement compared to clinical and laboratory parameters.
Methods. Seventeen [18F]-FDG PET/MRI examinations were performed in fourteen patients. Qualitative (visual 4-point scale) and quantitative PET parameters (maximum standardised uptake value, SUVmax; target-background ratio, TBR) as well as RF thickness and volume were correlated to clinical and inflammatory parameters and compared between therapy-naive patients and patients under immunosuppression. Evidence for associated large-vessel vasculitis was examined. Magnetic resonance angiography (MRA) was performed to detect aneurysms or stenoses.
Results. Clinical parameters, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) only incompletely displayed inflammatory activity and did not correlate with PET/MRI parameters. In 29% (4/17) resp. 50% (8/16) of PETI MRI examinations active disease was detected although CRP resp. ESR were in the normal range. SUVmax, TBR and volume of the retroperitoneal mass differed significantly between therapy-nave patients and patients under therapy (SUVmax p=0.004, TBR p=0.015, volume p=0.015), whereas thickness of the retroperitoneal mass did not (p=0.406). Large-vessel vasculitis was detected in 21% (3/14) and aortic aneurysms in 14% (2/14) of patients. Vasculitis occurred apart from the site of RF in two patients.
Conclusion. Whole body hybrid [[18F]-FDG-PETI-MRI is superior to clinical and inflammatory parameters in disease activity assessment of RF. There may be substantial disease activity despite inflammatory parameters in the normal range. Associated large-vessel vasculitis and aneurysms may occur apart from the site of RF.

• 出版日期2017-2