Role of FDG-PET/CT in children with fever of unknown origin

Jordy P Pijl; Thomas C Kwee; G E Legger; Helja J H Peters; Wineke Armbrust; E H Schölvinck; Andor W J M Glaudemans

doi:10.1007/s00259-020-04707-z

Role of FDG-PET/CT in children with fever of unknown origin

Eur J Nucl Med Mol Imaging. 2020 Jun;47(6):1596-1604. doi: 10.1007/s00259-020-04707-z. Epub 2020 Feb 7.

Authors

Jordy P Pijl¹, Thomas C Kwee², G E Legger³, Helja J H Peters³, Wineke Armbrust³, E H Schölvinck⁴, Andor W J M Glaudemans²

Affiliations

¹ Medical Imaging Center, Department of Radiology, Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands. j.p.pijl@umcg.nl.
² Medical Imaging Center, Department of Radiology, Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
³ Beatrix Children's Hospital, Department of Pediatric Rheumatology and Immunology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
⁴ Beatrix Children's Hospital, Department of Pediatric Infectious Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.

Abstract

Purpose: To determine the role of ¹⁸F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET)/computed tomography (CT) in children with fever of unknown origin (FUO).

Methods: This retrospective single-center study included 110 children (0-18 years) with FUO who underwent FDG-PET/CT between 2010 and 2019. The diagnostic value of FDG-PET/CT for identifying cause of fever was calculated, treatment modifications after FDG-PET/CT were assessed, and logistic regression analyses were performed to identify clinical and biochemical factors associated with FDG-PET/CT outcome.

Results: In 53 out of 110 patients (48%), FDG-PET/CT identified a (true positive) cause of fever. Endocarditis (11%), systemic juvenile idiopathic arthritis (5%), and inflammatory bowel disorder (5%) were the most common causes of FUO. In 42 patients (38%), no cause of fever was found on FDG-PET/CT. In 58 out of 110 patients (53%), treatment modifications were made after FDG-PET/CT. FDG-PET/CT achieved a sensitivity of 85.5%, specificity of 79.2%, positive predictive value of 84.1%, and negative predictive value of 80.9%. On multivariate logistic regression, C-reactive protein was positively associated with finding a true positive focus of fever on FDG-PET/CT (OR = 1.01 (95% CI 1.00-1.02) per mg/L increase in CRP), while leukocyte count was negatively associated with finding a true positive focus of fever (OR = 0.91 (95% CI 0.85-0.97) per 10⁹ leukocytes/L increase).

Conclusion: FDG-PET/CT is a valuable diagnostic tool in the evaluation of children with FUO, since it may detect a true underlying cause in almost half (48%) of all cases where none was found otherwise. It allows full-body evaluation in patients without disease-specific symptoms on one examination. CRP and leukocyte count were significantly associated with FDG-PET/CT results, which may contribute to a priori assessment on the outcome of FDG-PET/CT. Future research could be aimed at evaluating more patient-specific factors to prospectively estimate the added value of FDG-PET/CT in children with FUO.

Keywords: Fever; Infection; Inflammation; Origin; Pediatrics; Unknown.

MeSH terms

Child
Fever of Unknown Origin* / diagnostic imaging
Fever of Unknown Origin* / etiology
Fluorodeoxyglucose F18*
Humans
Positron Emission Tomography Computed Tomography
Positron-Emission Tomography
Radiopharmaceuticals
Retrospective Studies
Tomography, X-Ray Computed

Substances

Radiopharmaceuticals
Fluorodeoxyglucose F18