68ga-psma pet/ct versus18f-fdg pet/ct for imaging of hepatocellular carcinoma

Abstract

Objectives: This study aimed to compare the metabolic parameters obtained from18fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) and gallium-68 (68Ga)-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, and18F-FDG and68Ga-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 (SUVmax ) of these regions were compared with the SUVmax of primary tumor (T). Results: On visual assessment, five patients (36%) experienced low18F-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 low68Ga-PSMA uptake, two patients (14%) showed moderate uptake, and 11 patients (79%) showed high uptake. Four patients with a low18F-FDG uptake showed high68Ga-PSMA uptake, while one patient exhibited low uptake with both18F-FDG and68Ga-PSMA. The number of lesions on68Ga-PSMA PET/CT and MRI was significantly higher than18F-FDG PET/CT (p=0.042 and 0.026, respectively). T/A and T/G values were significantly higher in68Ga-PSMA than 18 F-FDG (p=0.002 and 0.002, respectively). Conclusion:68Ga-PSMA PET/CT is superior to18F-FDG PET/CT in the staging of hepatocellular carcinoma. High68Ga-PSMA uptake could be promising for PSMA-targeted radionuclide treatments.