Superior Identification of Metastatic Lesions by 68Ga-FAPI-46 PET/CT Than 18F-FDG PET/CT in Hepatic Solitary Fibrous Tumor

Abstract Solitary fibrous tumors (SFTs) are fibroblast tumors that occur mainly in the pleura. Hepatic SFT with skeleton metastases was rarely documented. In this case, we report the contrast-enhanced CT, 18 F-FDG, and 68 Ga-FAPI-46 PET/CT findings of a rare hepatic SFT with bone metastases. 68 Ga-FAPI-46 PET/CT showed much higher tumor-to-background contrast of hepatic tumors and revealed more metastatic bone lesions than 18 F-FDG PET/CT. This case demonstrated the superiority of 68 Ga-FAPI-46 PET/CT over 18 F-FDG for identifying metastatic lesions in malignant SFTs. This observation may add information on the benefit of FAPI PET/CT in SFT staging.