Study on the Value of Non-invasive Dual-Pet Information in Subtype of Metastatic Breast Cancer

Inclusion Criteria: 1. Subjects voluntarily joined the study, signed informed consent, and had good compliance. 2. Female patients aged over 18 years (including cutoff value). 3. an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2. 4. Recurrence or metastatic breast cancer confirmed by histopathology, or expect to be feasible metastasis puncture or surgery to confirm histopathological recurrence or metastatic breast cancer. Exclusion Criteria: 1. Pregnancy or lactation. 2. Alcohol allergy is not suitable for FES-PET/ C. 3. There are contraindications for patients who are expected to have metastasis puncture or surgery. 4. Mental disorders or other conditions affecting patient compliance.