68Ga-FAPI Versus 18F-FDG PET/CT in Evaluating Newly Diagnosed Breast Cancer Patients A Head-to-Head Comparative Study

PurposeThis study aimed to compare the performance of Ga-68-FAPI and F-18-FDG PET/CT in the evaluation of patients with newly diagnosed breast cancer.MethodsThirty-four women with newly diagnosed breast cancer who underwent both Ga-68-FAPI and F-18-FDG PET/CT within 1 week were prospectively included in the study. The imaging characteristics of primary lesions, diagnostic efficiency of lymph node metastasis (LNM), and accuracy of N stage evaluation between 2 PET/CTs were compared.Results(68)Ga-FAPI showed higher SUVmax (11.06 +/- 5.48 vs 8.33 +/- 6.07, P = 0.02) and tumor-to-background ratio (15.32 +/- 10.33 vs 8.25 +/- 5.51, P < 0.001) than F-18-FDG in primary tumors. Ga-68-FAPI SUVmax was positively correlated with the pathological grade of the primary lesions and the final stage of the patients (P < 0.001). The specificity and accuracy of Ga-68-FAPI was higher than that of F-18-FDG in the diagnosis of LNMs on patient-based and lesion-based analysis (P < 0.001). The accuracy for the evaluation of N stage and N0 axillar status was 91.2% (31/34) and 85.7% (12/14) for Ga-68-FAPI, and 73.5% (25/34) and 42.9% (6/14) for F-18-FDG, respectively.ConclusionsThe Ga-68-FAPI SUVmax was positively correlated with the pathological grade of the primary lesions and the final stage of the patients. Ga-68-FAPI PET/CT has higher accuracy than F-18-FDG in the evaluation of N stage, especially N0 axillar status, which is helpful to improve the treatment strategy for breast cancer patients.