The yield of F18 FDG PET-CT for the investigation of fever of unknown origin, compared with diagnostic CT

• Published in: European journal of internal medicine 2021-11, Vol.93, p.50-56
• Main Authors: Buchrits, S., Gafter-Gvili, A., Eynath, Y., Bernstine, H., Guz, D., Avni, T.
• Format: Article
• Language: English
• Subjects: Fever of unknown origin; FUO; PET-CT; Sensitivity; Specificity
• ISSN: 0953-6205; 1879-0828
• DOI: 10.1016/j.ejim.2021.07.014

•PET-CT is recommended as a first or a second-line imaging method for the evaluation of patients with FUO. We evaluated the yield of PET-CT vs. contrast enhanced CT (alone) for the diagnosis of classical FUO.•A single center, 8-year retrospective cohort study. All hospitalized patients who underwent PET-CT for the investigation of classical FUO between were included. For each case, we determined whether the diagnosis would have been reached based on the CT scan alone, or based on the PET-CT•A total of 303 patients with classical FUO were referred for PET-CT.•PET-CT had superior sensitivity vs CT (p=0.00) for all subgroups, with generally decreased specificity than CT for infections and inflammatory conditions. PET-CT was determined as necessary in 26% (79/303) of the patients.•Endovascular infection, hematological malignancy and large vessel vasculitis were the only factors associated with PET-CT necessity on multivariable analysis. 18F-Fluoro-2-deoxy-D-glucose (FDG) positron emission tomography, with contrast enhanced CT (PET-CT), is recommended as a first or a second-line imaging method for the evaluation of patients with fever of unknown origin (FUO). We evaluated the yield of PET-CT vs. contrast enhanced CT (alone) for the diagnosis of classical FUO. A single center, 8-year retrospective cohort study. All hospitalized patients who underwent PET-CT for the investigation of classical FUO between 1/2012-1/2020 were included. The final diagnosis, based on clinical, microbiological, radiological and pathological data available at the latest follow-up, at least six months after discharge, was determined. For each case, we determined whether the diagnosis would have been reached based on the CT scan alone, or based on the PET-CT (thus, defining PET-CT as necessary). We compared the overall sensitivity and specificity results for both PET-CT and CT scan. Variables that were found to be significantly associated with PET-CT necessity on univariable analysis were entered into a multivariable logistic regression analysis. The results of the regression model were reported in odds ratios (OR) and 95% confidence intervals (CI). A total of 303 patients with classical FUO were referred for PET-CT. The final diagnoses included infectious diseases in 111/303 patients (36.5%), malignancies in 56/303 patients (18.4%) and non-infectious inflammatory conditions in 52/303 patients (17.1%). FUO resolved without diagnosis in 84/303 patients (28%). The overall sensitivity and sp