The efficacy of 18F-FDG PET/CT and 67Ga SPECT/CT in diagnosing fever of unknown origin

• Published in: International journal of infectious diseases 2017-09, Vol.62 (C), p.10-17
• Main Authors: Hung, Bor-Tau, Wang, Pei-Wen, Su, Yu-Jih, Huang, Wen-Chi, Chang, Yen-Hsiang, Huang, Shu-Hua, Chang, Chiung-Chih
• Format: Article
• Language: English
• Subjects: 18F-FDG PET/CT; 67Ga SPECT/CT; Fever of unknown origin
• ISSN: 1201-9712; 1878-3511
• DOI: 10.1016/j.ijid.2017.06.019

Fever of unknown origin (FUO) is a diagnostic challenge. This study aimed to assess the efficacy of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and gallium-67 single-photon emission computed tomography/computed tomography (67Ga SPECT/CT) in diagnosing FUO. A total of 68 patients with FUO underwent 18F-FDG PET/CT and 67Ga SPECT/CT from January 2013 through May 2016. Images were read independently. The imaging results were compared with the final diagnosis and categorized as helpful for diagnosis or non-contributory to diagnosis in the clinical setting. Associations between categorical variables were evaluated with the chi-square test or Fisher’s exact test. Ten of the 68 patients were excluded. An infectious underlying disease was found in 23 patients. A malignant disorder was the cause of FUO in 10 patients. Non-infectious inflammatory disease was found in 11 patients. Adrenal insufficiency was the cause of FUO in two patients. The cause of FUO was not found for 12 patients. A high false-positive rate of 44% (7/16) was observed for 18F-FDG PET/CT, while a high false-negative rate of 55% (23/42) was observed for 67Ga SPECT/CT. 18F-FDG PET/CT studies depicted all 67Ga-avid lesions. The sensitivity (79% vs. 45%) and clinical contribution (72% vs. 55%) of 18F-FDG PET/CT in diagnosing FUO were significantly higher than those of 67Ga SPECT/CT (p