The value of FDG-PET/CT in diagnosis and during follow-up of 271 patients suspected of chronic Q fever

C.P. Bleeker-Rovers, I.J.E. Kouijzer, L.M. Kampschreur, P.C. Wever, C. Hoekstra, M.E.E. van Kasteren, M.G.L. de Jager-Leclercq, M.H. Nabuurs-Franssen, M.C.A. Wegdam-Blans, L.-F. de Geus-Oei, W.J.G. Oyen

Woensdag 20 april 2016

15:20 - 15:30u in Zaal 2.1

Categorie├źn: Parallelsessie

Parallel sessie: Parallelsessie 5: Case reports/research

Background: Diagnosis of chronic Q fever is often difficult, because symptoms may be aspecific and foci are often not visible on conventional imaging. We investigated the diagnostic value of FDG-PET/CT in chronic Q fever at the time of diagnosis and during follow-up.

Methods: All Dutch adult patients suspected of chronic Q fever, detected since the start of the Dutch Q fever epidemic in 2007, were retrospectively included until March 2015 when at least one FDG-PET/CT was performed. Clinical data and results from FDG-PET/CT at diagnosis and during follow-up were collected.

Results: 271 patients were included. Of 145 patients with proven chronic Q fever, 63 patients (43.4%) were diagnosed with infected vascular prostheses, 33 patients (22.8%) had an infected aneurysm, and 13 patients (9.0%) had definite endocarditis according to the revised Duke criteria. Of all 271 FDG-PET/CT scans performed at diagnosis, 36 scans (13.3%) led to a change in diagnosis and 48 scans (17.7%) led to treatment adjustment. Of all 173 scans performed during follow-up in 99 patients (median 2 scans per patient), 3 scans (1.8%) led to a change in diagnosis and 114 scans (65.9%) led to treatment adjustment.

Conclusions: FDG-PET/CT is a valuable diagnostic technique in localizing chronic Q fever and during follow-up often leading to a change in diagnosis and/or adjustment of treatment. After reevaluation of all FDG-PET/CT scans by one experienced nuclear medicine physician (WJGO), we will examine whether adding FDG-PET/CT to the revised Duke criteria can improve these criteria in diagnosing chronic Q fever endocarditis.