[18F]-Fluoro-2-deoxy-D-galactose positron emission tomography/computed tomography as complementary imaging tool in patients with hepatocellular carcinoma

Background & Aims: Positron emission tomography (PET) with the liver-specific tracer [18F]-fluoro-2-deoxy-D-galactose (18F-FDGal) can be used for imaging of hepatocellular carcinoma (HCC). Curative intended and locoregional treatments of HCC require absence of extrahepatic disease. The aim of this prospective study was to determine whether adding 18F-FDGal PET/CT to standard work-up changes the planned treatment in patients with HCC deemed suitable for curative or locoregional treatment. Methods: Fifty patients with HCC were included at our tertiary liver centre. The primary study outcome was a change in treatment strategy. A subgroup of 29 patients was also examined with [18F]-fluoro-2-deoxy-D-glucose (18F-FDG) PET/CT for comparison. Results: 18F-FDGal PET/CT detected eight extrahepatic HCC metastases in six patients (12%), which were primarily not detected by ceCT or MRI. These findings led to a change in treatment in five patients (10%). One of the eight extrahepatic HCC foci was also detected by 18F-FDG PET/CT. A total of 85 malignant intrahepatic foci were examined, 12 of these were new findings by 18F-FDGal PET/CT which had a sensitivity of 71%, highest for large foci. None of the additional intrahepatic foci found by 18F-FDGal PET changed the planned treatment. Conclusions: For the detection of extrahepatic HCC metastases, 18F-FDGal PET/CT was superior both to standard clinical work-up with contrast-enhanced CT, and/or MRI, and to 18F-FDG PET/CT in patients deemed suitable for locoregional treatment. 18F-FDGal PET/CT led to a change in the planned treatment in 10% of the patients whereas 18F-FDG PET/CT did not change the planned treatment in any patient.