Impact of fat intake on [18F]AlF-NOTA-FAPI-04 uptake in normal abdominal organs

Purpose [F-18]AlF-NOTA-FAPI-04 demonstrates significant physiological uptake in the gallbladder and biliary tract system, representing a limitation of this positron emission tomography (PET) tracer. The aim of this study was to evaluate the impact of milk consumed prior to a PET/CT scan on [F-18]AlF-NOTA-FAPI-04 uptake in normal abdominal organs. Materials and methods A total of 86 patients who underwent [F-18]AlF-NOTA-FAPI-04 PET/CT imaging took part in this single-center retrospective clinical study at the Hunan Cancer Hospital between December 2020 and August 2021. Patients were divided into two groups according to their pre-PET scan diet: treated group, who consumed 250 mL of milk 10 +/- 5 min after the tracer injection, while the control group was permitted no food intake subsequent to the radiotracer administration. The mean standardized uptake value (SUVmean) of gallbladder, liver, small intestine and pancreas were measured in F-18-FAPI and F-18-FDG PET/CT. Results There was a statistically significant difference in the F-18-FAPI uptake in the gallbladder between the treated group and the control group (p < 0.001). The average SUVmean in the treated group was 2.19 +/- 2.01, which was significantly lower than the average SUVmean of 10.04 +/- 9.66 in the control group. In the subgroup analysis of patients who underwent paired [F-18]FDG and [F-18]FAPI PET/CT scans, the F-18-FAPI uptake of liver and small intestine was significantly lower than the F-18-FDG uptake in both the treated group and the control group (p < 0.001). Conclusion This study suggests that milk consumption decreases physiological F-18-FAPI uptake in the gallbladder, potentially enhancing the diagnostic accuracy for gallbladder cancer.