This is an open-label positron emission tomography/computed tomography(PET/CT) study to investigate the diagnostic performance and evaluation efficacy of 68Ga-NOTA-RM26 in breast tumor patients. 1.85 MBq per kilogram body weight of 68Ga-NOTA-RM26A will be injected intravenously. Visual and semiquantitative method will be used to assess the PET/CT images.

The gastrin-releasing peptide receptor (GRPR), also known as bombesin receptor subtype II (BB2), is a member of the G protein-coupled receptor family of bombesin receptors. GRPR is over-expressed in various types of human tumors including breast cancer. RM26, a GRPR antagonist with high affinity, was discovered by peptide backbone modification of bombesin analogues.To target gastrin-releasing peptide receptor in neoplastic cells of human breast cancer, peptide NOTA-RM26 was synthesized with a PEG3 linker between NOTA and RM26, and then labeled with 68Ga. An open-label whole-body PET/ CT study was designed to assess its clinical diagnostic value in patients with breast tumor.

Inclusion Criteria:

• patients in suspicion of breast cancer by mammography or ultrasonography,and being able to provide basic information and sign the written informed consent form

Exclusion Criteria:

• The exclusion criteria included claustrophobia, pregnancy, breastfeeding, kidney or liver failure, inability to fulfill the study, and undergoing any preceding local or systemic therapies that might interfere with GRPR binding