Mammosite® Brachytherapy is a new form of internal radiation therapy that is used following a lumpectomy (the surgical removal of a tumor from the breast). It is either used with external beam radiation therapy or by itself to kill any cancer cells remaining after surgery. Treatment is done on an outpatient basis, and entire procedure usually lasts for a total of 5 days.
Images used in planning MammoSite treatment.
The white area is the inflated balloon; the yellow and blue circles
show the spread of radiation during treatment.
Mammosite is used following surgical removal of the tumor. A balloon catheter (a flexible plastic container attached to a thin plastic tube) is placed into the empty space made when the tumor was removed. The balloon is filled with fluid, so that the balloon fits into the cavity in your breast. The filled balloon stays in the body during the treatment course.
In treatment, the tube is attached to a machine called an afterloader. The afterloader inserts a "seed" (a tiny piece of radioactive material attached to a thin wire) into the balloon. The machine controls the amount of radiation released, which has been planned by your radiation oncologist. After about 10 minutes of treatment, the seed is withdrawn. Treatment sessions typically occur twice a day for five days. Once the treatment is completed, the balloon is drained and removed, and the cavity is allowed to heal.
Mammosite provides radiation directly to the tissue next to the removed cancer (which would be the most likely place where new tumors would return), while traditional radiation treatments treat the whole breast. Treatment is also shorter than with traditional radiation therapy, which can last 7 weeks.