Propionic Acid-Based PET Imaging of Prostate Cancer.

Purpose: This study aimed to evaluate the potential value of 2-[F]fluoropropionic acid ([F]FPA) for PET imaging of prostate cancer (PCa) and to explore the relationship between [F]FPA accumulation and fatty acid synthase (FASN) levels in PCa models. The results of the first [F]FPA PET study of a PCa patient are reported.

Procedures: The LNCaP, PC-3 cell lines with high FASN expression, and DU145 cell lines with low FASN expression were selected for cell culture. A PET imaging comparison of [F]FDG and [F]FPA was performed in LNCaP, PC-3, and DU145 tumors. Additionally, in vivo inhibition experiments in those models were conducted with orlistat. In a human PET study, a patient with PCa before surgery was examined with [F]FPA PET and [F]FDG PET.

Results: The uptake of [F]FPA in the LNCaP and PC-3 tumors was higher than that of [F]FDG (P<0.05 and P<0.05), but was lower in DU145 tumors (P<0.05). The accumulation (% ID/g) of [F]FPA in the LNCaP, PC-3, and DU145 tumors decreased by 27.6, 40.5, and 11.7 %, respectively, after treatment with orlistat. The [F]FPA showed higher radioactive uptake than [F]FDG in the first PCa patient.

Conclusions: The [F]FPA uptake in PCa models may be varies with fatty acid synthase activity and could be reduced after administration of a single FASN inhibitor, albeit the activity that is not measured directly. The [F]FPA seems to be a potential broad-spectrum PET imaging agent and may serve as a valuable tool in the diagnosis of PCa in humans.