Prospective Comparison of [F]FDG and [F]AIF-FAPI-74 PET/CT in the Evaluation of Potentially Resectable Pancreatic Ductal Adenocarcinoma.

Purpose: Accurate clinical staging of potentially resectable pancreatic ductal adenocarcinoma (PDAC) is critical for establishing optimal treatment strategies. While the efficacy of fluorine-18-fluorodeoxyglucose ([F]FDG) positron emission tomography/computed tomography (PET/CT) in clinical staging is unclear, PET/CT detecting fibroblast-activation protein (FAP) expression has recently received considerable attention for detecting various tumors, including PDAC, with high sensitivity. We explored the efficacy of [F]FDG and [F]AIF-FAPI-74 PET/CT in the initial evaluation of potentially resectable PDAC.

Procedures: Between 2021 and 2022, twenty participants with newly diagnosed potentially resectable PDAC were enrolled. After the initial evaluation with pancreatic CT, [F]FDG PET/CT, and [F]AIF-FAPI-74 PET/CT, treatment strategies were determined considering the participant's general status, clinical staging, and resectability. Pathological information from the surgical specimens was only available in 17 participants who underwent curative-intent surgery. Head-to-head comparisons of quantitative radiotracer uptake and diagnostic performance were performed among imaging modalities.

Results: [F]AIF-FAPI-74 PET/CT showed a significantly higher maximum standardized uptake value than [F]FDG PET/CT did in evaluating primary pancreatic lesions (median [interquartile range]; 12.6 [10.7-13.7] vs. 6.3 [4.8-9.2]; P < 0.001). In contrast, [F]AIF-FAPI-74 PET/CT showed a significantly lower mean standardized uptake value than [F]FDG PET/CT did in evaluating background organ (median [interquartile range]) 0.8 [0.7-0.9] vs. 2.6 [2.3-2.7]; P < 0.001). In addition, the sensitivity of [F]AIF-FAPI-74 PET/CT in detecting metastatic lymph nodes was higher than that of [F]FDG PET/CT (50.0% vs. 0.0%; P = 0.026).

Conclusion: This study demonstrated that [F]AIF-FAPI-74 PET/CT could improve the clinical staging of potentially resectable PDAC.