When radioactive beads are injected into the artery feeding the livers of colorectal cancer patients, the time before liver tumors get worse increases, as well as the time to overall cancer progression in the body.

In a process called radioembolization, resin beads loaded with yttrium-90, a radioactive isotope, are injected directly to the  large artery leading to the liver (hepatic artery).  They travel to the tiny blood vessels around liver tumors and emit radiation for about 14 days.

Because tumors receive their blood supply primarily through the hepatic artery while healthy liver receives blood through the portal vein, healthy liver tissue is spared radiation.

The yttrium-90 radioembolization treatment is known as selective internal radiation therapy(SIRT) or SIR-Spheres. Read the rest of this entry »

SIRT Microspheres

When surgery is not possible to remove colorectal cancer that has spread to the liver, inserting radioactive beads into the liver through its large artery may reach tumors and destroy them.

Called Selective Internal Radiation Therapy or SIRT, either resin carrying radioactive Yttrium-90 are inserted into the liver through a catheter in the hepatic artery in the groin. The tiny microspheres travel through the artery into the rich system of blood vessels that feed liver tumors. The beads get trapped in the tiny blood vessels near tumors and emit radiation that destroys cancer cells.

Radiation continues for about 14 days. After that the tiny beads, each less than a third of the diameter of a single strand of hair, remain safely within the liver.

Radiation from microspheres affects only tumors within the liver and doesn’t harm other parts of the body.

Before treatment begins, a planning angiogram is necessary. Resin beads without radioactive Yttrium are inserted through the hepatic artery and followed to be sure that the system of liver blood vessels will let them reach the tumors and not go beyond the liver where radiation could hurt other parts of the body.

SIRT treatment is delivered by an interventional radiologist with special training and experience with the procedure. Find a center where the procedure is done.

Currently, SIRT is covered by Medicare and many insurance companies for people whose colorectal cancer has already gotten worse on chemotherapy and who are not appropriate for liver surgery.

Where Can You Go for More Information

• View a recording of our patient webinar, “Treating Liver Metastases” 
• SIRTEX, the manufactures of SIR-Spheres resin microspheres has information especially for patients on their website, including frequently asked questions and some excellent videos.
• Support and information for patients by patients is available from YES, both online and via toll-free telephone.