Yttrium Y 90 Glass Microspheres

**Semantic type:** Drug Delivery Device|Pharmacologic Substance

**Definition:** An injectable formulation of yttrium Y 90 consisting of glass microspheres containing the radioisotope yttrium Y 90. When injected into the tumor vascular bed, yttrium Y 90 glass microspheres occlude tumor blood vessels and deliver a cytotoxic dose of beta radiation to the tumor site, thereby reducing the tumor burden. (NCI04)

**Synonyms:** - TheraSphere - Y-90 Therasphere