Abstract
BACKGROUND: In the present study, we investigated the value of (18)F-fibroblast-activation protein inhibitor (FAPI) positron emission tomography/computed tomography ((18)F-FAPI-42 PET/CT) to preoperative evaluations of appendiceal neoplasms and management for patients. METHODS: This single-center retrospective clinical study, including 16 untreated and 6 treated patients, was performed from January 2022 to May 2023 at Southern Medical University Nanfang Hospital. Histopathologic examination and imaging follow-up served as the reference standard. (18)F-FAPI-42 PET/CT was compared to (18)F-fluorodeoxyglucose ((18)F-FDG) PET/CT and contrast-enhanced CT (CE-CT) in terms of maximal standardized uptake value (SUVmax), diagnostic efficacy and impact on treatment decisions. RESULTS: The accurate detection of primary tumors and peritoneal metastases were improved from 28.6% (4/14) and 50% (8/16) for CE-CT, and 43.8% (7/16) and 85.0% (17/20) for (18)F-FDG PET/CT, to 87.5% (14/16) and 100% (20/20) for (18)F-FAPI-42 PET/CT. Compared to (18)F-FDG PET/CT, (18)F-FAPI-42 PET/CT detected more regions infiltrated by peritoneal metastases (108 vs. 43), thus produced a higher peritoneal cancer index (PCI) score (median PCI: 12 vs. 5, P < 0.01). (18)F-FAPI-42 PET/CT changed the intended treatment plans in 35.7% (5/14) of patients compared to CE-CT and 25% (4/16) of patients compared to (18)F-FDG PET/CT but did not improve the management of patients with recurrent tumors. CONCLUSIONS: The present study revealed that (18)F-FAPI-42 PET/CT can supplement CE-CT and (18)F-FDG PET/CT to provide a more accurate detection of appendiceal neoplasms and improved treatment decision making for patients.