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.
