Comparison of 18F-FDG and 68Ga-FAPI-04 Uptake in Postoperative Re-evaluation of Gastric, Duodenal, and Colorectal Cancers

PurposeTo compare the potential efficacy of Ga-68-FAPI-04 PET/CT with that of F-18-FDG PET/CT for detecting tumor recurrence and nodal and distant metastases in gastric, duodenal, and colorectal cancers.MethodsThis single-center retrospective clinical study was performed at the Affiliated Hospital of Southwest Medical University between January 2020 and June 2022. Participants with gastric, duodenal, and colorectal cancers after curative resection underwent both Ga-68-FAPI-04 and F-18-FDG PET/CT. Histopathologic examination, morphologic imaging, and/or follow-up imaging served as the reference standards. The SUVmax of the tumor recurrence and nodal and distant metastases between F-18-FDG and Ga-68-FAPI-04 PET/CT were compared using the paired-sample t test.ResultsForty-one participants with gastric, duodenal, and colorectal cancers were enrolled in the study (median age, 51 years; range, 19-75 years). The sensitivity of Ga-68-FAPI-04 PET/CT was higher than that of F-18-FDG PET/CT for detecting tumor recurrence (6 of 6 [100%] vs 4 of 6 [67%]), nodal metastases (92 of 92 [100%] vs 31 of 92 [34%]), and distant metastases (28 of 30 [93%] vs 20 of 30 [67%]).Conclusion(68)Ga-FAPI-04 PET/CT for tumor re-evaluation showed potential for more accurate performance of gastric, duodenal, and colorectal cancers, thereby improving treatment decision-making.