Background/aims: The goal of this study was to assess the clinical usefulness of 18F-FDG PET/ CT for investigating unexplained serum AFP elevation following interventional therapy such as transarterial chemoembolization (TAE) or radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC).
Methodology: A retrospective study was conducted involving 18 HCC patients (9 men and 9 women; age, 42-67 years) who underwent 18F-FDG PET/CT for evaluation of AFP without evidence of HCC recurrence on multiphasic abdominal CT after TAE or RFA treatment. The results of the 18F-FDG PET/CT were compared with histological, radiological and clinical follow-up.
Results: Among 18 patients, 14 patients demonstrated HCC recurrence (10 intrahepatic, 3 extrahepatic and 1 intrahepatic/extrahepatic). Metastatic foci were found in the lung (1 patient), bone (1 patient), lymph node (1 patient), and adrenal gland (1 patient). The 18F-FDG PET/CT identified seven intrahepatic and four extrahepatic lesions. Overall, the 18F-FDG PET/CT had nine true-positives, five false-negatives, four true-negatives and zero false-positives for the detection of HCC recurrence. The sensitivity, specificity and accuracy were 64%, 100% and 72%, respectively.
Conclusions: When the multiphasic CT was normal, the 18F-FDG PET/CT was valuable to reveal intrahepatic tumor recurrence and/or extrahepatic metastases in patients with AFP elevation after interventional therapy for HCC.