Head-to-head comparison of [18F]-FDG and [68 Ga]-DOTA-FAPI-04 PET/CT for radiological evaluation of platinum-sensitive recurrent ovarian cancer

Purpose Precise radiological evaluation is pivotal for the management of platinum-sensitive recurrent ovarian cancer. We aimed to compare the value of [(68) Ga]-FAPI and [F-18]-FDG PET/CT for the detection of relapsed lesions.Methods Twenty-nine suspected platinum-sensitive recurrent ovarian cancers were enrolled from January 2022 to July 2022. [F-18]-FDG and [(68) Ga]-FAPI PET/CT were obtained within 1 week for radiological evaluation. Treatment strategies, visual scores, and Eisenkop scores were recorded. A paired T test was used to compare differences between two scans. Sensitivity, specificity, PPV, NPV, and accuracy were also evaluated.Results Up to 22 (75.86%) patients displayed inconsistency between two scans. Among them, 4 patients with negative [F-18]-FDG imaging had measurable lesions in [(68) Ga]-FAPI scans. The treatment strategies were changed in 5 patients (17.24%) due to discrepancies. Finally, 15 (35.7%) patients underwent surgeries, and 14 patients achieved complete resection, except for 1 patient who had milliarc residual disease. TBR, but not SUVmax, of [(68) Ga]-FAPI was significantly higher than that of [F-18]-FDG in recurrent lesions. Compared with [F-18]-FDG, [(68) Ga]-FAPI PET presented higher sensitivity and accuracy for lesion detection (96.30% vs. 49.07% and 97.40% vs. 63.87%, respectively). Additionally, [(68) Ga]-FAPI PET showed a much higher visual score than [F-18]-FDG PET (41 vs. 4), especially for peritoneal metastasis (35 vs. 1). [(68) Ga]-FAPI PET also presented a larger tumor burden than [F-18]-FDG according to the Eisenkop score (27 vs. 16, p = 0.025).Conclusions [(68) Ga]-FAPI was superior to [F-18]-FDG PET/CT for the detection of recurrent lesions, which is pivotal for the individualized management of platinum-sensitive recurrent ovarian cancer.