68Ga-FAPI-04 Versus 18F-FDG PET/CT in the Detection of Hepatocellular Carcinoma
Hao Wang, Wenwei Zhu, Shuhua Ren, Yanyan Kong, Qi Huang, Jun Zhao, Yihui Guan, Huliang Jia, Jinhong Chen, Lu Lu, Fang Xie, Lun–Xiu Qin
Abstract
Background Fibroblast activation protein (FAP) is commonly expressed in activated stromal fibroblasts in various epithelial tumours. Recently, 68 Ga-FAPI-04 has been used for tumour imaging in positron emission tomography/computed tomography (PET/CT). This study aimed to compare the diagnostic performances of 68 Ga-FAPI-04 PET/CT and 18 F-FDG PET/CT in hepatocellular carcinoma (HCC), and to assess factors associated with 68 Ga-FAPI-04 uptake in HCC. Materials and Methods Twenty-nine patients with suspiciously HCC who received both 18 F-FDG and 68 Ga-FAPI-04 PET/CT were included in this retrospective study. The results were interpreted by two experienced nuclear medicine physicians independently. The maximum and mean standardized uptake values (SUV max and SUV mean ) were measured in the lesions and liver background, respectively. The tumour-to-background ratio (TBR) was then calculated as lesion’s SUV max divided by background SUV mean . Results A total of 35 intrahepatic lesions in 25 patients with HCC were finally involved in the statistical analysis. 68 Ga-FAPI-04 PET/CT showed a higher sensitivity than 18 F-FDG PET/CT in detecting intrahepatic HCC lesions (85.7% vs . 57.1%, P = 0.002), including in small (≤ 2 cm in diameter; 68.8% vs . 18.8%, P = 0.008) and well- or moderately-differentiated (83.3% vs . 33.3%, P = 0.031) tumors. SUV max was comparable between 68 Ga-FAPI-04 and 18 F-FDG (6.96 ± 5.01 vs . 5.89 ± 3.38, P > 0.05), but the TBR was significantly higher in the 68 Ga-FAPI-04 group compared with the 18 F-FDG group (11.90 ± 8.35 vs . 3.14 ± 1.59, P < 0.001). SUV max and the TBR in 68 Ga-FAPI-04 positive lesions were associated with tumour size (both P < 0.05), but not the remaining clinical and pathological features (all P > 0.05). Conclusions 68 Ga-FAPI-04 PET/CT is more sensitive than 18 F-FDG PET/CT in detecting HCC lesions, and 68 Ga-FAPI-04 uptake is correlated mainly with tumour size.