MammoSite Breast Brachytherapy

MammoSite was FDA approved in 2002 for post-lumpectomy breast cancer treatment. The MammoSite Radiation Therapy System uses a special balloon catheter, placed in your lumpectomy cavity and inflated with saline solution. Your surgeon can place a MammoSite balloon catheter at the time of your lumpectomy, or it may be inserted at a later time.

Advantages and Disadvantages of MammoSite Brachytherapy

MammoSite brachytherapy treatments can be completed in five to seven days, as compared to six to seven weeks of standard external radiation. This means less disruption of your schedule, less travel time, and

fewer copayments.

A very small portion of your breast will be treated by the radiation, and healthy tissue will be unaffected.

Your breast will have a surgical scar, but otherwise none of the skin burns or tissue thickening that may occur with standard radiation.

Standard radiation may cause fatigue, but with brachytherapy you will be able to go about life as usual. Patients say that having to avoid showers for a week is a disadvantage, and that the sensation of having a saline-filled balloon within a breast feels odd. Infections can occur around the catheter insertion site, but you can take antibiotics to combat that. Because a catheter line will extend out of your breast while the device is in place, you’ll need to wear a sports bra or a very comfortable bra to accommodate it, and adjust your sleeping position for comfort.

Mammosite Demonstration

How It Works

View a demonstration of this procedure:

MammoSite 5-Day Targeted Radiation Therapy simplifies breast cancer treatment

1. Placement

After the breast cancer tumor is removed (lumpectomy), a small, soft MammoSite balloon attached to a thin tube (catheter) is placed inside the lumpectomy cavity through a small incision in the breast.

  • The balloon is “inflated” with saline solution so that it fits snugly into the cavity. It remains inflated during the 5-day treatment.
  • A small portion of the catheter remains outside the breast; this is secured to a cushioned gauze pad to prevent movement of the catheter.


2. Treatment

  • Treatment is planned by a radiation oncologist who will take images of the MammoSite balloon catheter in the breast and determine the amount of radiation needed.
  • During therapy, the portion of the catheter that remains outside your breast is connected to a computer-controlled High Dose Rate (HDR) machine that inserts a radiation “seed” to deliver the therapy.
  • Once therapy is complete, the seed is removed, the catheter is unplugged, and you will be free to return to your normal daily activities.
  • No radiation remains inside your breast in between treatments.


3. Removal


  • After 5 days of treatment, your MammoSite balloon catheter will be removed, usually on the last day of treatment.
  • The balloon is gently removed through the same incision made to place it.


For more information visit MammoSite online.

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