What Is Mammosite Radiation Therapy for Breast Cancer?

Breast conservation procedures for early stage breast cancer has replaced mastectomy as the treatment of choice in the vast majority of patients. This entails a lumpectomy procedure where the surgeon removes the cancer from the breast with clear margins. This has traditionally been followed by whole breast radiation which prevents the cancer from coming back in that breast. This allows the woman to retain her breast and be free of her breast cancer. These treatments are done by a procedure called Tele-therapy which is done using giant x-ray machines, called LINACS. High energy x-rays are directed to the involved breast over a 6 to 7 week period, given 5 days a week. It takes about 15 to 20 minutes to deliver each treatment.

The problems that patients with early stage breast cancer face when undergoing whole breast radiation:

1. Since the whole breast is treated with radiation, surrounding tissues such as lung and heart would also receive some radiation.

2. The several weeks that it takes for the treatments to be completed can be a burden on the patient and the family emotionally.

3. Patients who need chemotherapy, are started on radiation after several months delay from surgery.

4. Accessibility to a radiation center because of distances involved and the financial burden of staying away from their home and family for several weeks in order to complete the prescribed course of radiation.

Do all patients need whole breast irradiation?

This was a question that was asked several years ago and the concept of Partial Breast Irradiation caught on. Several studies showing that selected patients with early stage breast cancer would do just as well with a shorter course of treatment done in 5 days. Unlike external beam radiation ( Teletherapy), this was done through internal radiation, also called brachy-therapy. One of the pioneering methods of performing this procedure was by using a device called Mammosite balloon catheter.

What is Mammosite radiation therapy?

The surgeon places the inflated balloon of the Mammosite catheter into the cavity that is created by removing the tumor at the time of the lumpectomy. The patient subsequently comes over to the Radiation Oncology center where the Mammosite catheter is attached to a High dose rate radiation machine which is a device that has a small radioactive source called Iridium 192. This radioactive seed is driven by motors into the middle of the Mammosite balloon through the catheter for a calculated amount of time, generally a few minutes. This allows for the radiation from the source to kill cancer cells in the immediate area around the lumpectomy cavity. These treatments are done twice a day for five days. Since the radiation is given from within the balloon located within the lumpectomy cavity, there is very little radiation that is given to the heart and lung tissues.

Which breast cancer patients get benefit from Mammosite treatments?

There are strict criteria that need to be met before a decision is made to proceed with this short 5 day course of radiation treatment.

1. Age more than 45 years.

2. Size of the tumor less than 3 cm.

3. Margins of resection of the cancer in the lumpectomy should be clear.

4. Lymph nodes should not have any evidence of breast cancer spread.

Advantages of Mammosite breast cancer treatment:

1. Radiation part of treatment is completed soon after surgery and the patient can go on for chemotherapy etc without any issues.

2. Procedure is well tolerated and minimal side effects.

3. Convenient and cost savings to insurance companies and patients compared to 7 week of external radiation.

If Mammosite is so convenient for patients, how come more cancer centers do not discuss this with their patients?

1. The Radiation centers and / or departments may not be equipped with the high dose rate radiation machine to perform this procedure.

2. The Radiation doctors may not have any training in this procedure.

3. The surgeons may not have any training in this procedure.

Dr. Kumar is a board certified Radiation Oncologist who is co-founder of a private practice group called Coastal Cyberknife and Radiation Oncology in Saint Lucie County, Florida. He has over 17 years experience dealing with breast cancer patients including several members in his own family who have been afflicted by this disease.