The Diagnostic Value of 18F-FDG PET/CT in Fever of Unknown Origin, MAGED A. HAMED, HALA Y. YOUSEF and SAEED B. EL-SAYED
Abstract
Introduction and Objective: Fever of unknown origin (FUO) is a challenging diagnostic problem. Timely identifica-tion and precise localization of the causing process are critical for appropriate patient management. The present prospective study evaluates the role of PET/CT using 18 F-FDG in the in-vestigation of FUO.
Methods: 48 patients were well documented and diagnosed as FUO and referred to our PET/CT unite to delineate the un-derlying etiology of this clinical complaint. The performance of PET/CT for identifying the etiology of FUO was assessed. Final diagnosis was based on histopathology, microbiologic as-says, or clinical and imaging follow-up.
Results: The positive result was achieved in 38 (79.2%) of 48 patients as findings of the FDG PET/CT. However, FDG PET/CT was useful for definitive diagnosis in 24 (63.2%) of 38 positive patients. Malignant diseases were determined to be the underlying cause of FUO in 10 (41.6%) of 24 patients. Noninfectious inflammatory causes were detected in 4 (16.7%) patients, infections were exhibited in 6 (25%) patients, and miscellaneous diseases demonstrated in 4 (16.7%) patients. In 14 patients the detected pathological uptakes on FDGPET/CT were not helpful for the definitive diagnosis. In remaining 10 patients who showed no pathological uptake in the FDG PET/ CT, diagnosis could not be established by other methods, as well. The sensitivity, specificity, and positive and negative predictive values for the determination of FUO etiology were 92.3%, 45.4%, 63.1%, and 100% for FDG PET/CT.
Conclusion: 18F-FDG PET/CT has a high negative predic-tive value (100%) for assessment of FUO. If confirmed by fur-ther studies, 18 F-FDG PET/CT may be used in the future as an initial noninvasive diagnostic modality for assessment of this group of patients.