Radioactive Distribution Patterns of [68Ga]Ga-FAPI-04 in Primary Hepatocellular Carcinoma

Purpose: To evaluate the radioactive distribution patterns of [ 68 Ga]Ga-FAPI-04 in primary hepatocellular carcinoma (HCC). Methods: Twenty-three primary HCC patients (26 lesions) from a prospective trial (ChiCTR2000039099) underwent both [ 18 F]FDG and [ 68 Ga]Ga-FAPI-04 PET/CT within 1 week. Uptake at tumor margins versus centers was compared. Results: FAPI-04 uptake was significantly higher at tumor margins than centers (SUVmax, P <0.001; SUVmean, P <0.01). As SUVmax thresholds increased, FAPI volume of interest concentrated at the margins and decreased sharply in the centers. Conclusions: [ 68 Ga]Ga-FAPI-04 PET/CT demonstrated higher marginal uptake and pronounced central heterogeneity (low-SUV centers) in HCC. Strong peripheral uptake supports the use of FAP-targeted fluorescence-guided surgery and targeted treatment of marginal residual/recurrent disease, while low central uptake may limit FAP-targeted therapy.