18F-FDG-PET/CT in unexplained elevated inflammatory markers. Joining entities.
The diagnostic strategy in patients with fever or inflammation of unknown origin remains a major clinical challenge. The aim of this study was to evaluate the role of18F-FDG-PET/CT in patients with unexplained elevated C-reactive protein with or without fever. Contribution of18F-FDG-PET/CT to the final diagnosis was evaluated. In addition we determined whether a differentiation between patients with or without fever is clinically reasonable.


METHODS
We retrospectively analysed 72 consecutive patients with unexplained elevated C-reactive protein levels (above 8mg/l) that underwent18F-FDG-PET/CT in our facility between 10/2009 and 11/2012.18F-FDG-PET/CT was considered a so-called diagnostic scan when results decisively led to a final diagnosis and adequate therapy with a response of symptoms was initiated due to the PET/CT result.


RESULTS
In 60/72 patients (83%) a final diagnosis was established. Diagnoses included infections (58%), non-infectious inflammatory diseases (29%) and malignancies (8%).18F-FDG-PET/CT was true positive in 47 cases (65%) and the diagnostic scan in 29 patients (40%). Sensitivity of18F-FDG-PET/CT was 81% and specificity was 86%. Diagnostics, final diagnoses,18F-FDG-PET/CT results, SUVmax, C-reactive protein levels and the diagnostic scan did not differ significantly between patients with fever and patients without fever.


CONCLUSIONS
18F-FDG-PET/CT is a useful method in the diagnostic workup of patients with inflammation of unknown origin. In our series there was no significant difference between patients with or without fever. Regarding18F-FDG-PET/CT-imaging inflammation of unknown origin and unexplained fever can be joined to one entity.
Caroline Bouter, Department of Nuclear Medicine, Georg-August-University Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany, E-Mail: caroline.bouter@med.uni-goettingen.de.
Caroline
C
Bouter
Isabell
I
Braune
Birgit
B
Meller
Carsten
C
Sahlmann
Carsten
C
Ritter
Johannes
J
Meller
D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000000981:diagnostic imaging*; D018836:Inflammation Mediators / Q000097:blood; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D064847:Multimodal Imaging / Q000379:methods*; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
D015415:Biomarkers; D018836:Inflammation Mediators; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D002097:C-Reactive Protein
18F-FDG-PET/CT; C-reactive protein; Fever; inflammation of unknown origin