Mammosite® Radiation Therapy System for Breast Cancer
Radiation oncologists at Huntington are offering radioactive seed implantation in the treatment of breast cancer. Mammosite® cuts treatment time from six weeks to one week while minimizing treatment side effects. Studies suggest that it is as effective as traditional radiation of the breast at preventing a recurrence of cancer.

The Mammosite® technique works by providing a mechanism for the radiation source to be placed inside the breast through a catheter that has been inserted either by the surgeon during the lumpectomy procedure, or under ultrasound guidance in the Radiation Therapy Department up to six weeks after surgery. This method enables physicians to deliver a higher dose of radiation directly to the tumor site. With traditional radiation therapy, the radiation emanates from an external source and radiates the entire breast, therefore a lower dose of radiation must be administered over a longer period of time.

“The goal of radiation therapy in the treatment of breast cancer is not to cure the cancer, but to decrease the possibility of a recurrence,” noted Richard Byrnes, MD, Chief of Radiation Oncology at Huntington. Studies have shown that 96% of women who do experience a recurrence do so in the same quadrant of the breast as the initial cancer occurred. “The Mammosite® allows us to treat just that quadrant.”

Mammosite® offers the ability to compress the duration of treatments from 33 doses given over six weeks, down to ten doses, administered twice a day for five days. “This can be a real benefit to elderly patients, as well as those who have difficulty traveling to the hospital for six weeks, and patients whose work schedules make it difficult for them to be available for a six week period, such as flight attendants,” said Dr. Byrnes.

Another benefit is that radiation can begin as soon as one week after surgery. With traditional radiation, physicians normally wait until the surgical site has completely healed, which can take two-to-six weeks.

Dr. Byrnes stressed that not every woman is a candidate for Mammosite®. “The procedure is currently recommended for women who are over 45, with a tumor that is less than two centimenters,” stated Dr. Byrnes. “The tumor must have been completely removed during surgery, and the cavity must be deep enough in the breast to prevent damage to the skin when the radioactive seed is placed in the breast.”

The Mammosite® procedure requires highly specialized equipment. It relies on a specialized catheter with a balloon-tipped end, which is inserted into the cavity that remains after the lumpectomy. During the treatment, the balloon is filled with water, and then the radioactive pellet is inserted into the catheter. The pellet is removed at the end of the treatment, and the woman is able to return to her normal activities, including being near small children, without concern about lingering radiation.

“Treatments are very well tolerated, with no nausea, hair loss, or other side effects,” explained Radiation Therapist Jeffrey Musmacher. “Some women notice redness over the balloon site for about one week after the treatment ends, while others report a temporary feeling of pressure within the breast.”

For additional information on the Mammosite, please call 631-351-2294.