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

OBJECTIVES

This prospective study aimed to investigate the potential of [F]-fibroblast activation protein inhibitor ([F]-FAPI)-04 PET/CT for evaluating suspected recurrent uterine malignancy after radical surgery, and prospectively compared it with [F]-Fluorodeoxyglucose ([F]-FDG) PET/CT.

METHODS

From August 2022 to August 2024, patients with suspected recurrent/metastatic uterine malignancy following radical surgery received both [F]-FDG PET/CT and [F]-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) 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 [F]-FAPI-04 and [F]-FDG PET/CT, with no significant differences in SUV and TBR. In nodal metastases assessment, [F]-FAPI-04 PET/CT exhibited superior detection capability over [F]-FDG PET/CT (p < 0.01), with the diagnostic advantage most evident in abdominal lymph node metastases. Visceral metastatic lesions demonstrated significantly elevated [F]-FAPI-04 PET/CT uptake parameters (SUV and TBR) compared to [F]-FDG PET/CT imaging, especially in peritoneal and brain metastases.

CONCLUSIONS

[F]-FAPI-04 PET/CT demonstrated superior detection capability for postoperative metastatic lesions in uterine cancer patients compared to [F]-FDG PET/CT, with particularly diagnostic advantage in abdominal lymph node, brain, and peritoneal metastases.