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 prostate cancer patients. A single dose of 111-148 Mega-Becquerel (MBq) 68Ga-NOTA-RM26 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 prostate 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 prostate 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 investigate the safety and dosimetry of 68Ga-NOTA-RM26 and to assess its clinical diagnostic value in patients with prostate cancer.

Inclusion Criteria:

• Patients with diagnosis of primary prostate cancer having a prostate neoplasm identified by ultrasound or MRI, being diagnosed by needle biopsy as having prostate cancer, having undergone whole-body bone scanning, and being able to provide basic information and sign the written informed consent form.

Exclusion Criteria:

• The exclusion criteria included claustrophobia, kidney or liver failure, and inability to fulfill the study.