Lutetium 177 is an isotope of a rare-earth lanthanide metal lutetium. Radioactive decay of Lu 177 produces electrons with low energies making the isotope suitable for treatment of metastatic disease. A complex of Lu177 and somatostatin analog DOTA-TATE was approved by the FDA for the treatment of somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors, including foregut, midgut, and hindgut neuroendocrine tumors in adults. It is marketed under a tradename Lutathera. Lutetium in the complex with other carriers - phosphonates and monoclonal antibodies - was investigated in clinical trials as radiotherapy to prostate, ovarian, renal and other types of cancer.