ABSTRACT
Objective:To exploring the uptake of fibroblast activation protein (FAP) inhibitor (FAPI) in pancreatic cancer through 68Ga-FAPI-04 PET/CT imaging, and provide a basis for the FAP-targeted imaging of pancreatic cancer. Methods:Pancreatic cancer-patient-derived tumor xenograft (PDX) mouse models ( n=8) were developed, then 68Ga-FAPI-04 and 18F-FDG microPET/CT imaging were performed (4 in each group). The differences of percentage activity of injection dose per gram of tissue (%ID/g) of 68Ga-FAPI-04 and 18F-FDG were analyzed by independent-sample t test. 68Ga-FAPI-04 and 18F-FDG PET/CT imaging were performed in 5 patients (4 males, 1 female, age: 46-74 (63.0±11.9) years) with pancreatic cancer, and the maximum standardized uptake value (SUV max) of 68Ga-FAPI-04 and 18F-FDG in primary pancreatic cancer and the SUV max ratio of liver metastases to liver tissue were compared by paired t test. Results:MicroPET/CT imaging showed that 68Ga-FAPI-04 was obviously uptaken at all time points in the tumor of PDX mice. The uptake of 68Ga-FAPI-04 in PDX mice 60 min after injection was significantly higher than that of 18F-FDG ((6.58±0.44) and (4.29±0.13) %ID/g; t=4.152, P=0.008 9). PET/CT showed that the SUV max of 68Ga-FAPI-04 in pancreatic cancer was significantly higher than that of 18F-FDG (16.82±3.08 and 5.14±2.20; t=6.893, P=0.000 1) and the SUV max ratio of liver metastases to liver tissue of 68Ga-FAPI-04 was also significantly higher than that of 18F-FDG (4.57±1.47 and 1.30±0.16; t=3.803, P=0.019 1). Conclusion:68Ga-FAPI-04 can be highly uptaken in pancreatic cancer, suggesting that FAP can be a potential target for PET/CT imaging of pancreatic cancer.