yttrium-90 colloid

Yttrium-90 (90Y) colloid is a radiopharmaceutical agent primarily utilized for local radiation therapy through intra-articular or intracavitary injection. It consists of the beta-emitting radioisotope yttrium-90, which has a physical half-life of 2.67 days and emits high-energy beta particles (Emax 2.27 MeV). These particles have a maximum tissue penetration of approximately 11 mm and a mean penetration of 3.6 mm, allowing for targeted destruction of diseased tissue while sparing adjacent healthy structures. Its primary applications include **radiosynoviorthesis (RSO)** for the treatment of chronic inflammatory synovitis (as seen in rheumatoid arthritis or osteoarthritis) and the management of **cystic brain lesions**, particularly craniopharyngiomas and Rathke cleft cysts. In RSO, the colloid is engulfed by synovial macrophages, leading to fibrosis and ablation of the hyperproliferative synovial membrane. In neuro-oncology, stereotactic intracavitary administration targets the cyst wall to reduce volume and prevent recurrence.

Brand names

Y-90 ColloidY90 ColloidY 90 ColloidY-90 Silicate ColloidY90 Silicate ColloidY 90 Silicate Colloid

Other names

yttrium (90Y) colloidyttrium-90 silicate colloidyttrium90 silicate colloidyttrium 90 silicate colloidyttrium-90 citrate colloidyttrium90 citrate colloidyttrium 90 citrate colloidyttrium-90 resin colloidyttrium90 resin colloidyttrium 90 resin colloidradiosynoviorthesis yttrium-90