(68)Ga-PSMA PET/CT Versus (18)F-FDG PET/CT for Imaging of Hepatocellular Carcinoma

OBJECTIVES: This study aimed to compare the metabolic parameters obtained from (18)fluorine-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) and gallium-68 ((68)Ga)-prostate-specific membrane antigen (PSMA) PET/CT and investigate the relationship between serum alpha-fetoprotein and PET scan parameters in patients with hepatocellular carcinoma. METHODS: Fourteen patients were recruited after dynamic magnetic resonance imaging (MRI) of the upper abdomen, and (18)F-FDG and (68)Ga-PSMA PET/CT imaging studies were conducted. Regions of interest (ROIs) were drawn from lesion-free liver tissue, abdominal aorta (A), and right medial gluteal muscle (G) for the background activity. Maximum standard uptake value (SUV(max)) of these regions were compared with the SUV(max) of primary tumor (T). RESULTS: On visual assessment, five patients (36%) experienced low (18)F-FDG uptake in the primary lesion, three patients (21%) experienced moderate uptake, and six patients (43%) experienced high uptake. However, only one patient (7%) showed low (68)Ga-PSMA uptake, two patients (14%) showed moderate uptake, and 11 patients (79%) showed high uptake. Four patients with a low (18)F-FDG uptake showed high (68)Ga-PSMA uptake, while one patient exhibited low uptake with both (18)F-FDG and (68)Ga-PSMA. The number of lesions on (68)Ga-PSMA PET/CT and MRI was significantly higher than (18)F-FDG PET/CT (p=0.042 and 0.026, respectively). T/A and T/G values were significantly higher in (68)Ga-PSMA than (18)F-FDG (p=0.002 and 0.002, respectively). CONCLUSION: (68)Ga-PSMA PET/CT is superior to (18)F-FDG PET/CT in the staging of hepatocellular carcinoma. High (68)Ga-PSMA uptake could be promising for PSMA-targeted radionuclide treatments.