A radioconjugate consisting of the octreotide derivative edotreotide labeled with yttrium 90 (Y-90) with potential radiotherapeutic uses. Similar to octreotide, yttrium Y 90-edotreotide binds to somatostatin receptors (SSTRs), especially type 2 receptors, present on the cell membranes of many types of neuroendocrine tumor cells, delivering tissue-specific, beta-emitting nuclide Y-90-mediated cytotoxicity to SSTR-positive cells. Yttrium Y 90-edotreotide is produced by substituting tyrosine for phenylalanine at the 3 position of the somatostatin analogue octreotide and chelating the substituted octreotide to Y-90 via dodecanetetraacetic acid (DOTA).