Comparison of different kinetic models for dynamic 68Ga-FAPI-04 PET/CT imaging of hepatocellular carcinoma with various, also dual-blood input function

Aim: The aim of the study is to establish a 68Ga-FAPI-04 dynamic model in hepatic lesions, to determine the potential role of kinetic parameters in the differentiation of hepatocellular carcinoma (HCC) from non-HCC lesions.Methods: 68Ga-FAPI-04 PET dynamic images of 7 HCC lesions and 5 non-HCC lesions from 8 patients were analyzed from their time-activity curve (TACs). Five kinetic models were applied to the TACs, using hepatic artery and/or portal vein as input functions. Results were analyzed according to Akaike and Schwartz information criteria.Results: A two-compartment model using solely a venous input function was most preferred and showed significant differences between healthy regions and lesions in almost all model parameters. Using a two-compartment model with one arterial input function delivered significant differences between HCC and non-HCC regions in the case of K1 (p = 0.03).Conclusion: The established FAPI PET dynamic model in liver lesions suggested that FAPI PET kinetic parameters have the potential to differentiate between HCC and non-HCC lesions.