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Radioembolization (TheraSphere®, SIR-Spheres®)


What is radioembolization (TheraSphere®, SIR-Spheres®)?

When cancer spreads, the liver is a common site for metastatic disease. Radioembolization (TheraSphere®, SIR-Spheres®) is an innovative therapy that delivers radiation directly to tumors in the liver.

How it works

Radioembolization uses tiny glass beads, called microspheres, to deliver radiation directly to cancerous tumors in the liver. Measuring one-third the diameter of a human hair, these tiny microspheres are embedded with a radioactive element to help kill liver cancer cells.

Radioembolization is delivered to a tumor through a catheter that the physician guides into the hepatic artery, the liver’s main blood vessel. Once in place, the microspheres are inserted into the catheter where they can enter the smaller blood vessels supplying the tumor and block the flow of blood. Then, the microspheres emit radiation to destroy cancer cells in the tumor, while sparing healthy liver tissue.

In some cases, a similar treatment that uses resin microspheres may be used instead.

TheraSphere® medical animation