Gallium Ga 68-NOTA-RM26

**Semantic type:** Organic Chemical|Pharmacologic Substance

**Definition:** A radioconjugate containing RM26, a synthetic bombesin analogue and antagonist of the gastrin-releasing peptide receptor (GRPR), that is linked, through the macrocyclic chelating agent 1,4,7-triazacyclononane-N,N',N''-triacetic acid (NOTA) to the radionuclide gallium (Ga) 68, with potential use in diagnostic imaging using positron emission tomography/computed tomography (PET/CT). Upon administration of gallium Ga 68-NOTA-RM26, the peptide moiety targets and binds to GRPR. Upon PET/CT, GRPR-expressing tumor cells can then be visualized. GRPR, also called bombesin receptor subtype 2 (BB2), is a G protein-coupled seven-transmembrane receptor belonging to the bombesin receptor family. It is overexpressed in certain types of cancers.

**Synonyms:** - 68Ga-NOTA-RM26