Value of 18F-FDG PET/CT in detecting viable tumour and predicting prognosis of hepatocellular carcinoma after TACE

AIM: To evaluate the efficacy of combined PET/CT in the detection of viable tumour in patients with hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE). The correlation between 2-[F-18]-fluoro-2-deoxy-D-glucose (FDG) uptake during PET and prognosis was evaluated. MATERIALS AND METHODS: Seventy-three patients with 91 HCCs who had undergone TACE with lipiodol before F-18-FDG PET/CT were retrospectively reviewed. The pattern of lipiodol deposition in the tumour was divided into three groups: grade I, lipiodol remaining in >= 60% of the tumour; grade II, 20-60%; and grade III, <= 20%. The performance of F-18-FDG PET/CT in evaluating the viability of HCC was assessed and compared with that of contrast-enhanced CT (CECT). The predictive value of maximal tumoural standardized uptake value (SUV) to mean liver SUV (T-SUVmax/L-SUVmean) ratio was tested. RESULTS: Comparing the receiver-operating characteristic area, F-18-FDG-PET/CT was found to be superior to CECT for the detection of viable tumour in patients with HCC after TACE (p = 0.04). A high SUV ratio (T-SUVmax/L-SUVmean >= 1.65) correlated significantly with tumour size (p = 0.0096), the grade of lipiodol deposition (p = 0.0387) and serum alpha-foetoprotein (AFP) level (p = 0.0142), but did not correlate with pathological grade (p = 0.2626). The overall survival rate was significantly higher in the low SUV ratio (T-SUVmax/L-SUVmean<1.65) group (p = 0.024). CONCLUSION: F-18-FDG-PET/CT is efficient in assessing the viability of HCC after TACE and is superior to CECT in grades I and II, and similar in grade III. It provides valuable information for prediction of prognosis and may aid decisions regarding treatment strategy. (C) 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.