Role of integrated PET/CT with [18F]-FDG in the management of patients with fever of unknown origin: a single-centre experience

Fever of unknown origin (FUO) is a diagnostic challenge for the wide range of possible causes involved. The aim of our work was to evaluate the role of [F-18]-fluorodeoxyglucose positron emission tomography computed tomography ([F-18]-FDG-PET/CT) in managing patients with classical FUO. Twenty-four consecutive patients (16 women, eight men; mean age, 56.5 years) with a diagnosis of FUO based on routine investigations were retrospectively studied. All underwent [F-18]-FDG-PET/CT, which was considered true positive when the result was in agreement with the final diagnosis. A final diagnosis was reached in 17 of 24 patients (vasculitis, n=5; autoimmune disorder, n=2; neoplasm, n=3; infectious disease, n=6; biliary microlithiasis, n=1). In the remaining seven cases, no final diagnosis was established. PET-CT was useful in identifying aetiology in 11 patients, showing a diagnostic yield of 46% (11/24). Among the 11 cases with a negative PET scan, 10 did not show a worsening of the clinical condition. This study underlines the crucial role of [F-18]-FDG-PET/CT in managing patients with FUO. If prospective trials on this topic confirm the present findings, PET/CT should be incorporated in the routine diagnostic work-up of patients with classical FUO.