yttrium (90Y) resin microspheres (Sirtex)

Yttrium-90 resin microspheres (commercially known as SIR-Spheres) are a targeted radiopharmaceutical medical device used in selective internal radiation therapy (SIRT), also known as transarterial radioembolization (TARE), for the treatment of unresectable primary and metastatic liver tumors. The therapy consists of biocompatible polymer resin microspheres (approximately 20 to 60 microns in diameter) loaded with the beta-emitting radioisotope yttrium-90 (Y-90). Administered via a catheter into the hepatic artery, these microspheres preferentially lodge in the microvasculature of hypervascular liver tumors, exploiting the fact that liver tumors derive over 90% of their blood supply from the hepatic artery. Once embolized, the microspheres deliver high-dose, localized beta radiation directly to the tumor cells, causing DNA damage and subsequent cell death while sparing the surrounding healthy liver tissue, which is primarily supplied by the portal vein. Yttrium-90 resin microspheres are FDA-approved for the treatment of unresectable metastatic liver tumors from primary colorectal cancer (in combination with intrahepatic artery floxuridine chemotherapy) and for unresectable hepatocellular carcinoma (HCC). They also hold CE Mark approval in Europe for broader indications, including intrahepatic cholangiocarcinoma (ICC) and hepatic metastases from neuroendocrine tumors (mNET).

Brand names

SIR-SpheresYiGanTai

Other names

Y-90 resin microspheresY90 resin microspheresY 90 resin microspheresresin microspheresyttrium Y-90 resin microspheresyttrium-90 resin microspheresyttrium90 resin microspheresyttrium 90 resin microspheres