Imaging infection with 18F-FDG-labeled leukocyte PET/CT: initial experience in 21 patients.
The aim of this study was to assess the feasibility and the potential role of PET/CT with (18)F-FDG-labeled autologous leukocytes in the diagnosis and localization of infectious lesions.


METHODS
Twenty-one consecutive patients with suspected or documented infection were prospectively evaluated with whole-body PET/CT 3 h after injection of autologous (18)F-FDG-labeled leukocytes. Two experienced nuclear medicine physicians who were unaware of the clinical end-diagnosis reviewed all PET/CT studies. A visual score (0-3)-according to uptake intensity-was used to assess studies. The results of PET/CT with (18)F-FDG-labeled white blood cell ((18)F-FDG-WBC) assessment were compared with histologic or biologic diagnosis in 15 patients and with clinical end-diagnosis after complete clinical work-up in 6 patients.


RESULTS
Nine patients had fever of unknown etiology, 6 patients had documented infection but with unknown extension of the infectious disease, 4 patients had a documented infection with unfavorable evolution, and 2 patients had a documented infection with known extension. The best trade-off between sensitivity and specificity was obtained when a visual score of >or=2 was chosen to identify increased tracer uptake as infection. With this threshold, sensitivity, specificity, and accuracy were each 86% on a patient-per-patient basis and 91%, 85%, and 90% on a lesion-per-lesion basis. In this small group of patients, the absence of areas with increased WBC uptake on WBC PET/CT had a 100% negative predictive value.


CONCLUSIONS
Hybrid (18)F-FDG-WBC PET/CT was found to have a high sensitivity and specificity for the diagnosis of infection. It located infectious lesions with a high precision. In this small series, absence of areas with increased uptake virtually ruled out the presence of infection. (18)F-FDG-WBC PET/CT for infection detection deserves further investigation in a larger prospective series.
Dumarey
Nicolas
N
Department of Nuclear Medicine and PET/Biomedical Cyclotron Unit, CUB-Hôpital Erasme, Université Libre de Bruxelles, Brussels, B-1070 Belgium. ndumarey@ulb.ac.be
Egrise
Dominique
D
Blocklet
Didier
D
Stallenberg
Bernard
B
Remmelink
Myriam
M
del Marmol
Véronique
V
Van Simaeys
Gaëtan
G
Jacobs
Frédérique
F
Goldman
Serge
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001170:Arthritis, Infectious / Q000000981:diagnostic imaging; D001424:Bacterial Infections / Q000000981:diagnostic imaging* / Q000188:drug therapy; D001528:Behcet Syndrome / Q000000981:diagnostic imaging; D017719:Diabetic Foot / Q000000981:diagnostic imaging; D004697:Endocarditis, Bacterial / Q000000981:diagnostic imaging; D005260:Female; D005335:Fever of Unknown Origin / Q000000981:diagnostic imaging; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage; D006801:Humans; D007962:Leukocytes; D008297:Male; D008875:Middle Aged; D010192:Pancreatic Pseudocyst / Q000000981:diagnostic imaging / Q000382:microbiology; D049268:Positron-Emission Tomography / Q000379:methods; D011446:Prospective Studies; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D051598:Whole Body Imaging
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18