new alternative for some women who have breast conserving surgery is
partial-breast irradiation. It works by delivering radiation from inside the
lumpectomy cavity (the space left after the tumor is removed) directly to the
tissue surrounding the cavity where the cancer is most likely to recur.
The mammosite is a 2-stage process: balloon placement and radiation delivery.
After the surgeon performs the lumpectomy, an uninflated delivery balloon
connected to a catheter, is placed inside the cavity where the tumor was. A
portion of the catheter remains outside of the breast. Once in place, the
balloon is inflated with a sterile salt water solution to fit snugly into your
lumpectomy cavity. The balloon remains inflated for the entire time you are
receiving radiation therapy (usually 5 days).
Treatment is given using the HDR delivery system using a treatment plan
developed to precisely specify radiation source position and dwell time. It is
delivered on an outpatient basis twice a day for 5 days, usually.
During radiation therapy, the balloon catheter will be connected to the
computer-controlled HDR machine. A tiny radioactive seed will travel from the
machine, through the catheter and into the inflated balloon. The seed will
remain in the balloon and deliver radiation for about 10 minutes. The seed is
then withdrawn back into the machine. No radiation will remain after the source
is retracted. After the last treatment, the balloon is deflated and easily