
The SIR-Sphere by Sirtex is a radioactive polymer sphere that emits beta radiation and is the only FDA-approved microsphere therapy for advanced colorectal cancer that has spread to the liver.
Physicians insert a catheter through the groin into the hepatic artery and deliver millions of SIR-Sphere microspheres directly to the tumor site.
The minimally invasive procedure is performed on an outpatient basis, leaving the patient with minor side effects.