[18F]-FAPI-04 PET/CT improves metastatic lesions detection for patients with uterine malignancy after radical surgery: prospectively compared with [18F]-FDG PET/CT

Abstract

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 (SUV_max) 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 SUV_max 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 (SUV_max 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.