RT Journal Article SR Electronic T1 The Value of 18F-FDG PET/CT in Diagnosis and During Follow-up in 273 Patients with Chronic Q Fever JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 127 OP 133 DO 10.2967/jnumed.117.192492 VO 59 IS 1 A1 Ilse J.E. Kouijzer A1 Linda M. Kampschreur A1 Peter C. Wever A1 Corneline Hoekstra A1 Marjo E.E. van Kasteren A1 Monique G.L. de Jager-Leclercq A1 Marrigje H. Nabuurs-Franssen A1 Marjolijn C.A. Wegdam-Blans A1 Heidi S.M. Ammerlaan A1 Jacqueline Buijs A1 Lioe-Fee de Geus-Oei A1 Wim J.G. Oyen A1 Chantal P. Bleeker-Rovers YR 2018 UL http://jnm.snmjournals.org/content/59/1/127.abstract AB In 1%–5% of all acute Q fever infections, chronic Q fever develops, mostly manifesting as endocarditis, infected aneurysms, or infected vascular prostheses. In this study, we investigated the diagnostic value of 18F-FDG PET/CT in chronic Q fever at diagnosis and during follow-up. Methods: All adult Dutch patients suspected of chronic Q fever who were diagnosed since 2007 were retrospectively included until March 2015, when at least one 18F-FDG PET/CT scan was obtained. Clinical data and results from 18F-FDG PET/CT at diagnosis and during follow-up were collected. 18F-FDG PET/CT scans were prospectively reevaluated by 3 nuclear medicine physicians using a structured scoring system. Results: In total, 273 patients with possible, probable, or proven chronic Q fever were included. Of all 18F-FDG PET/CT scans performed at diagnosis, 13.5% led to a change in diagnosis. Q fever–related mortality rate in patients with and without vascular infection based on 18F-FDG PET/CT was 23.8% and 2.1%, respectively (P = 0.001). When 18F-FDG PET/CT was added as a major criterion to the modified Duke criteria, 17 patients (1.9-fold increase) had definite endocarditis. At diagnosis, 19.6% of 18F-FDG PET/CT scans led to treatment modification. During follow-up, 57.3% of 18F-FDG PET/CT scans resulted in treatment modification. Conclusion: 18F-FDG PET/CT is a valuable technique in diagnosis of chronic Q fever and during follow-up, often leading to a change in diagnosis or treatment modification and providing important prognostic information on patient survival.