Y90 or Yttrium 90 is a very potent radioisotope which is used to treat liver tumors and this may be labeled with a spheres and which are used in patients with Hepatocellular carcinoma or in certain metastasis sometimes also in neuroendocrine tumors or they may be labeled with somatostatin receptor analog like dotatoc or dotatate and in such situation, this is called Y90 PRRT. Now Y90 PRRT may be used either by itself or it may be used along with Lutetium Therapy in alternating kind of protocol so you give one dose of Lutetium PRRT followed by a dose of Y90 again followed by Lutetium Therapy along with next dose as Y90. So this is called Tandem Therapy and this is very effective in patients who’ve got a large volume diseases.