SSTR2 and neuroendocrine neoplasm: Peptide receptor radionuclide therapy (PRRT) using radiolabeled somatostatin analogs is in clinical use for the treatment of neuroendocrine neoplasms (NENs) for many years, in particular for metastatic or unresectable progressive cases with a high tissue concentration of somatostatin type 2 receptors (SSTR2) 1.