Abstract:Objective: The aim of this study was to evaluate the value of 18F-FDG PET/CT in investigating hepatocellular carcinoma(HCC) with unexplained serum AFP elevation following surgical resection, transarterial chemoembolization(TACE) or radiofrequency ablation(RFA). Methods: A retrospective study was conducted involving 17 HCC patients who underwent 18F-FDG PET/CT to explain the evaluation of AFP without evidence of HCC recurrence examined by routine imaging. The 18F-FDG PET/CT results were correlated with histological findings, as well as long-term radiological and clinical follow-up(shortest follow-up period after FDG-PET was 6 months). Results: Among 17 patients, 12 patients demonstrated HCC recurrence(6 intrahepatic, 3 extrahepatic and 3 intrahepatic/extrahepatic). Metastatic foci were found in lymph node(3 patients), bone(1 patient), lung and muscle(1 patient), lung and crura of diaphragm (1 patient). The 18F-FDG PET/CT identified 7 intrahepatic and 6 extrahepatic. Overall, 18F-FDG PET/CT had 10 true-positives, 3 false-negatives, 4 true-negatives and no false-positives for the detection of HCC recurrence. The sensitivity, specificity, positive predictive value and negative predictive value were 77%, 100%, 82%, 100%, 57%, respectively. Conclusions: When conventional examinations are normal, the 18F-FDG PET/CT examination is a valuable imaging tool in patients who have elevated AFP value after HCC treatment.