Reviewed by Joe Maloney, M.D.Radiation therapy is treatment with high-energy rays or particles aimed at a tumor to destroy cancer cells. Doctors may elect for radiation therapy as a means of shrinking a tumor before surgery or another procedure, such as a bone marrow or stem cell transplant. Doctors may also elects for radiation therapy after a tumor has been removed, to destroy cancer cells remaining in the breast.
External beam radiation is the most common radiation therapy for breast cancer patients. External beam radiation focuses abeam of radiation from a source out side the body, much like an x-ray. The radiation team will determine the proper angles and locations for focusing the beam, and make measurements on the skin to use as a guide. The procedure usually takes a few minutes. Patients receive radiation therapy in an outpatient setting, five days a week for a period of several weeks.
The side effects from radiation therapy are fatigue, heaviness, swelling and changes on the skin. Women receiving radiation therapy should avoid sun exposure because of their skin sensitivity. Also, doctors advise women to abstain from antiperspirant use, as it interferes with the radiation.
Internal radiation
Internal radiation or brachytherapy is an experimental radiation therapy. Instead of delivering the radiation from outside the body, doctors place radioactive substances directly in the breast tissue, next to the cancer. This method of treatment concentrates radiation on the cancer cells and lessens damage to healthy tissue around the cancer. Doctors insert narrow tubes, seeds, or capsules into the breast tissue next to the tumor, to deliver a radioactive substance called Iridium 192 directly into the breast tissue. The Iridium 192 is removed after one week. Currently, doctors use brachytherapy to treat cancers of the head and neck, breast, uterus, thyroid, cervix, and prostate. Research suggests that it is a good alternative to surgical removal of the prostate, cervix, or breast – and reduces the risk of certain long term side effects.
MammoSite
The MammoSite Radiation Therapy System is the most widely used method of partial breast irradiation that works by delivering radiation from inside the breast directly to the tissue where cancer is most likely to recur. The use of this method following a lumpectomy is becoming the preferred way to minimize radiation exposure to healthy breast tissue.
After a lumpectomy is performed, an un-inflated MammoSite balloon is placed directly inside the cavity through a small incision in the breast. The balloon is then inflated with saline to fit snugly into the cavity. A portion of the catheter remains outside of the breast. Next, a radiation oncologist takes images of the MammoSite balloon in the breast to determine the amount of radiation therapy needed. Treatment consists of visits to the radiation oncology office twice per day for five days. The part of the catheter left outside of the breast is attached to a computer-controlled machine, from which a radioactive seed travels through the catheter and into the balloon inside the breast. The seed delivers radiation for 10 minutes and is then drawn back into the machine. On the last day of treatment, the balloon is deflated and removed.
Because radiation is only delivered to the affected area and no radiation remains in the body between treatments, the potential for side effects is reduced. Some women in clinical trials did experience minor breast-related side effects, such as redness, bruising, and breast pain. MammoSite is generally recommended for early-stage breast cancer patients and you should consult with your doctor before deciding to have this procedure.
