Predictors of Diagnostic Contributions and Spontaneous Remission of Symptoms Associated with Positron Emission Tomography with Fluorine-18-Fluorodeoxy Glucose Combined with Computed Tomography in Classic Fever or Inflammation of Unknown Origin: a Retrospective Study
Seiichiro Tsuzuki, Ayumi Watanabe, Mitsunaga Iwata, Hiroshi Toyama, Teruhiko Terasawa
Abstract
BACKGROUND: In patients with fever or inflammation of unknown origin (fever of unknown origin [FUO] or inflammation of unknown origin [IUO], respectively), expert consensus recommends the use of positron emission tomography with fluorine-18-fluorodeoxy glucose combined with computed tomography (FDG-PET/CT) when standard work-up fails to identify diagnostic clues. However, the clinical variables associated with successful localization of the cause by FDG-PET/CT remain uncertain. Moreover, the long-term outcomes of patients with unexplained FUO or IUO after negative FDG-PET/CT results are unknown. Therefore, we assessed predictors of successful diagnosis of FUO or IUO caused by FDG-PET/CT and associations of spontaneous remission of symptoms with FDG-PET/CT results. METHODS: All patients with FUO or IUO, who underwent FDG-PET/CT from 2013 to 2019 because diagnostic work-up failed to identify a cause, were retrospectively included. We calculated the diagnostic yield and performed multivariable logistic regression to assess characteristics previously proposed to be associated with successful localization of FUO or IUO causes. We also assessed whether the FDG-PET/CT results were associated with spontaneous remissions. RESULTS: = 0.018). CONCLUSION: In the current cohort, the proposed variables were not predictive for successful localization by FDG-PET/CT. A negative FDG-PET/CT scan may be prognostic for spontaneous remission in patients with sustained FUO or IUO.