Objectives: This prospective study aimed to investigate the potential of [18F]-fibroblast activation protein inhibitor ([18F]-FAPI)-04 PET/CT for evaluating suspected recurrent uterine malignancy after radical surgery, and prospectively compared it with [18F]-Fluorodeoxyglucose ([18F]-FDG) PET/CT.
Methods: From August 2022 to August 2024, patients with suspected recurrent/metastatic uterine malignancy following radical surgery received both [18F]-FDG PET/CT and [18F]-FAPI-04 PET/CT examinations, with imaging data prospectively evaluated. The comparative diagnostic efficacy of two PET/CT modalities for recurrence detection was statistically assessed using McNemar's test and the difference of lesion tracer uptake parameters [Maximum standardized uptake value (SUVmax) and Tumor-to-Background Ratio (TBR)] were analyzed by Wilcoxon signed-rank tests.
Results: 36 patients with 482 local relapses and distant metastases were included. Local relapses demonstrated comparable diagnostic performance between [18F]-FAPI-04 and [18F]-FDG PET/CT, with no significant differences in SUVmax and TBR. In nodal metastases assessment, [18F]-FAPI-04 PET/CT exhibited superior detection capability over [18F]-FDG PET/CT (p < 0.01), with the diagnostic advantage most evident in abdominal lymph node metastases. Visceral metastatic lesions demonstrated significantly elevated [18F]-FAPI-04 PET/CT uptake parameters (SUVmax and TBR) compared to [18F]-FDG PET/CT imaging, especially in peritoneal and brain metastases.
Conclusions: [18F]-FAPI-04 PET/CT demonstrated superior detection capability for postoperative metastatic lesions in uterine cancer patients compared to [18F]-FDG PET/CT, with particularly diagnostic advantage in abdominal lymph node, brain, and peritoneal metastases.
Keywords: Cancer-Associated Fibroblasts; Lymph node metastases; Peritoneal Metastases; Uterine malignancy recurrence; [(18)F]-FAPI-04 PET/CT; [(18)F]-FDG PET/CT.
Copyright © 2025. Published by Elsevier B.V.