SIR-Spheres microspheres are a medical device
used in Selective Internal Radiation Therapy (SIRT). The
microspheres are extremely small resin beads (about one-third the
diameter of a strand of hair) which contain radioactive yttrium-90
The radioactive microspheres are injected into
the main artery that supplies liver tumors, and because of their
small size and weight, are taken by the blood flow to the small
blood vessels surrounding the tumor where they lodge.
Radioactivity is then delivered directly to the
tumor cells in order to destroy them.
®SIR-Spheres is a registered trademark of Sirtex SIR-Spheres Pty Ltd.