169 Riverside Drive, Binghamton, NY 13905
Phone: 607-798-5230 • Fax: 607-798-6720
The MammoSite Radiation Therapy System (RTS) is a device that is
used to deliver radiation therapy after a woman undergoes a
lumpectomy, or surgical removal of the cancerous tumor. This
device delivers radiation from within the space left after the
cancerous tumor is removed, to the tissue directly surrounding that
cavity where tumors are most likely to recur. MammoSite
reduces the course of treatment from the traditional six weeks
to five days.
How does it
During a lumpectomy or shortly after, a single balloon catheter
is inserted through a small incision into the cavity created by the
surgical removal of the tumor (Figure 1). The balloon
tipped end is inflated with sterile saline and contrast (for
imaging) to fill the cavity. A portion of the catheter
remains outside of the breast and is dressed before the patient is
sent home (Figure 2).
The patient will then return to Lourdes for her daily radiation
therapy treatments. Typical treatment duration is twice a day
for five days (each visit to the doctor will take about an hour,
with 15 minutes or less for radiation delivery). During the
visit, the portion of the catheter remaining outside of the breast
is attached to a computer controlled machine, called an
afterloader. The afterloader is programmed to deliver a
radioactive seed, attached to a wire into the balloon portion of
the device where it emits radiation from within the breast (Figure
3). The patient may return home between treatments.
When radiation treatment has ended, the balloon is deflated and
easily removed (Figure 4).
Is the radiation exposure potentially harmful to the
Because the MammoSite RTS balloon catheter delivers radiation
from within, directly to the tissue surrounding the original tumor,
potential exposure to the rest of the breast, skin, ribs, lungs and
heart is minimized. No source of radiation remains in the
patient's body between treatments or after the final procedure.
Safety and performance of the device for delivery of internal
radiation were proven clinically in a multi-center study, which
involved women with early-stage breast cancer. The results of the
study were published in the International Journal of
Radiology*Biology*Physics (February 2003).
Is the MammoSite RTS similar to brachytherapy?
The MammoSite RTS is a device that delivers brachytherapy, a
term applied to the process of radiating from within. Conventional
breast brachytherapy has not been widely accepted by physicians and
patients because of its invasiveness and complexity. Conventional
brachytherapy requires the use of 15 to 30 catheters and is complex
for the physician to perform. In contrast, MammoSite RTS enables
treatment to be delivered with a single balloon catheter, and the
procedure is relatively quick and simple to perform, with minimal
discomfort to the patient.
Is treatment with the MammoSite RTS covered by health
Radiation therapy with internal radiation is an accepted
treatment for breast cancer and is covered by most insurers.
Specific coverage for the MammoSite RTS will depend on a patient's
individual health care plan.
Can any breast cancer patient be treated with the MammoSite
No. The use of MammoSite RTS is subject to physicians'
clinical judgement in consultation with their patients. To date,
physicians have generally recommended MammoSite for patients 45
years of age and older with early-stage breast cancer (e.g., a
tumor size of three centimeters or less and no nodal
Does treatment with MammoSite RTS cause side effects?
MammoSite RTS has been carefully tested in a clinical trial.
Following the treatment, study participants experienced
breast-related side effects, such as but not limited to redness,
bruising and breast pain. All of these are common side effects of
breast surgery and/or radiation therapy, and are usually only
temporary. The MammoSite RTS has been used to treat thousands of
patients, and a patient registry has been initiated to follow
patients treated with MammoSite.
Ask your physician about MammoSite RTS
for the treatment of Breast Cancer.