PET Imaging of Hepatocellular Carcinomas: 18 F-Fluoropropionic Acid as a Complementary Radiotracer for 18 F-Fluorodeoxyglucose

Abstract

Objective: To evaluate the preclinical value of 18 F-fluoropropionic acid ( 18 F-FPA) and 18 F-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography (PET) for imaging HCCs. Methods: The 18 F-FPA and 18 F-FDG uptake patterns in 3 HCC cell lines (Hep3B, HepG2, and SK-Hep1) were assessed in vitro and in vivo. The 18 F-FPA uptake mechanism was investigated using inhibition experiments with orlistat and 5-tetradecyloxy-2-furoic acid. The 18 F-FPA PET imaging was performed in different tumor animal models and compared with 18 F-FDG. We also evaluated the expressions of glucose transporter-1 (GLUT1), fatty acid synthase (FASN), and matrix metalloproteinase-2 (MMP2) in these cell lines. Results: In vitro experiments showed that the radiotracer uptake patterns were complementary in the HCC cell lines. Orlistat and 5-tetradecyloxy-2-furoic acid decreased the uptake of 18 F-FPA. The tumor-to-liver ratio of 18 F-FPA was superior to that of 18 F-FDG in the SK-Hep1 and HepG2 tumors (P