yttrium-90

Yttrium-90 (Y90) is a high-energy, pure beta-emitting radioactive isotope with a physical half-life of approximately 64.1 hours. It is widely utilized in oncology for selective internal radiation therapy (SIRT), also known as transarterial radioembolization (TARE), particularly for unresectable primary and metastatic liver tumors. The isotope is typically delivered via glass (TheraSphere) or resin (SIR-Spheres) microspheres injected into the hepatic artery, where they lodge in the tumor's microvasculature, delivering localized, lethal radiation while sparing healthy liver tissue. Beyond liver-directed therapy, Y90 is investigated for intratumoral brachytherapy in pancreatic cancer and has historical use in radiosynovectomy for rheumatoid arthritis. Its high energy (maximum 2.27 MeV) allows for a mean tissue penetration of approximately 2.5 mm, enabling targeted destruction of malignant cells through ionizing radiation-induced DNA damage.

Brand names

TheraSphereSIR-Spheres

Other names

Yttrium-90Yttrium90Yttrium 90Y90Y-90Y 90[90Y]yttriumyttrium Y-90yttrium (90Y) chloride