Yttrium Y 90 Colloid

**Semantic type:** Pharmacologic Substance

**Definition:** An injectable, colloidal formulation of the radioisotope yttrium Y 90, with potential antineoplastic activity. When injected into the tumor, the yttrium Y 90 colloid selectively delivers a cytotoxic dose of beta-emitting yttrium Y 90 to the tumor site, which may result in both tumor cell death and tumor regression.

**Synonyms:** - 90Y Colloid