The aim of this study is to compare the diagnostic performance of 68Ga-FAPI-46 PET/CT and 18F-FDG PET/CT in primary and metastatic lesions of breast cancer and to reveal the best diagnostic imaging time of 68Ga-FAPI-46 PET/CT.

Participants with breast carcinoma will undergo contemporaneous 18F-FDG and 68Ga-FAPI PET/CT. Tumor uptake will be quantified by the maximum standard uptake value (SUVmax). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of 18F-FDG and 68Ga-FAPI PET/CT will be calculated and compared to evaluate the diagnostic efficacy. In addition, best diagnostic imaging time of 68Ga-FAPI-46 PET/CT will be evaluated at 10th, 30th and 60th minute scan time.

Inclusion Criteria:

• adult participants (aged 18 years or order);
• participants with newly diagnosed breast carcinoma;
• pathology confirmed by lesion tru-cut biopsy;
• participants who were able to provide informed consent.

Exclusion Criteria:

• participants with non-malignant lesions;
• participants with pregnancy;
• the inability or unwillingness of the research participant, parent or legal representative to provide written informed consent.