Copper Cu-64 dotatate is a radioactive diagnostic drug. It binds to somatostatin receptors with highest affinity for subtype 2 receptors (SSTR2). It binds to cells that express somatostatin receptors including malignant neuroendocrine cells, which overexpress SSTR2 receptors. Copper Cu 64 is a positron (beta+) emitting radionuclide with an emission yield that allows positron emission tomography (PET) imaging.