Background Numerous studies have investigated the diagnostic accuracy of various PET tracers in breast cancer, with particular attention to the performance of fibroblast activation protein inhibitors (FAPI) relative to 18 F-fluorodeoxyglucose ( 18 F-FDG). This meta-analysis systematically reviews and compares the diagnostic performance metrics of FAPI PET versus 18 F-FDG in the clinical assessment of breast cancer. Methods A comprehensive search of PubMed and Web of Science identified clinical studies published between January 2018 and May 2025 that directly compared the two modalities. Sixteen studies involving 401 patients and 2,655 lesions were included. Data were analyzed at both patient- and lesion-based levels. Results Overall, FAPI PET demonstrated higher pooled sensitivity than 18 F-FDG PET for primary tumor detection (patient-based: 97% vs 89%, P = 0.02; lesion-based: 96% vs 84%, P = 0.03). For lymph node metastases, FAPI PET also showed superior sensitivity (patient-based: 96% vs 80%, P = 0.003; lesion-based: 96% vs 67%, P <0.001). Lesion-based analyses indicated greater sensitivity of FAPI PET for liver (97% vs 67%, P <0.001) and bone metastases (100% vs 65%, P <0.001), although patient-based differences were not statistically significant (liver: 89% vs 77%, P = 0.22; bone: 96% vs 90%, P = 0.23). Conclusion These findings suggest that FAPI PET imaging demonstrates superior diagnostic performance compared with 18 F-FDG in the detection and characterization of breast cancer. It holds significant promise for initial diagnosis, tumor staging, and the identification of recurrent or metastatic lesions. Given its advantages, FAPI PET may serve as a reliable alternative to 18 F-FDG PET for diagnosing both primary and metastatic breast cancer.
Ruan et al. (Tue,) studied this question.