Place of the 18F-FDG-PET/CT in the Diagnostic Workup in Patients with Classical Fever of Unknown Origin (FUO)

Simon Letertre (1, 2, 3) , Pierre Fesler (4, 5) , Laetitia Zerkowski (1, 2, 3) , Marie-Christine Picot (6) , Jean Ribstein (1, 2, 3) , Philippe Guilpain (7, 2, 3) , Vincent Le Moing (2, 3) , Denis Mariano-Goulart (4, 5) , Camille Roubille (4, 5)

1 CHU - Hôpital Lapeyronie [Montpellier]
2 CHU Montpellier
3 UM - Université de Montpellier
4 PhyMedExp - Physiologie & médecine expérimentale du Cœur et des Muscles [U 1046]
5 CHRU Montpellier - Centre Hospitalier Régional Universitaire [Montpellier]
6 CIC Montpellier
7 CHRU Montpellier - Hôpital Saint Eloi

Objective: To explore the diagnostic contribution of the 18F-FDG-PET/CT in a population of patients with classical fever of unknown origin (FUO), to pinpoint its place in the diagnostic decision tree in a real-life setting, and to identify the factors associated with a diagnostic 18F-FDG-PET/CT.Method: All adult patients (aged ≥ 18 years) with a diagnosis of classical FUO who underwent an 18F-FDG-PET/CT in the University Hospital of Montpellier (France) between April 2012 and December 2017 were included. True positive 18F-FDG-PET/CT, which evidenced a specific disease causing FUO, were considered to be contributive.Results: Forty-four patients with FUO have been included (20 males, 24 females; mean age 57.5 ± 17.1 years). Diagnoses were obtained in 31 patients (70.5%), of whom 17 (38.6%) had non-infectious inflammatory diseases, 9 had infections (20.5%), and 3 had malignancies (6.8%). 18F-FDG-PET/CT was helpful for making a final diagnosis (true positive) in 43.6% of all patients. Sensitivity and specificity levels were 85% and 37%, respectively. A total of 135 investigations were performed before 18F-FDG-PET/CT, mostly CT scans (93.2%) and echocardiography (59.1%), and 108 after 18F-FDG-PET/CT, mostly biopsies (including the biopsy of a temporal artery) (25%) and MRIs (34%). In multivariate analysis, the hemoglobin level was significantly associated with a helpful 18F-FDG-PET/CT (p = 0.019, OR 0.41; 95% CI (0.20–0.87)), while the CRP level was not associated with a contributive 18F-FDG-PET/CT.Conclusion: 18F-FDG-PET/CT may be proposed as a routine initial non-invasive procedure in the diagnostic workup of FUO, especially in anemic patients who could be more likely to benefit from 18F-FDG-PET/CT.

Domaines: Imagerie; Médecine humaine et pathologie

Simon Letertre, Pierre Fesler, Laetitia Zerkowski, Marie-Christine Picot, Jean Ribstein, et al.. Place of the 18F-FDG-PET/CT in the Diagnostic Workup in Patients with Classical Fever of Unknown Origin (FUO). Journal of Clinical Medicine, 2021, 10 (17), pp.3831. ⟨10.3390/jcm10173831⟩. ⟨hal-03342388⟩