Radiation therapy is an extremely effective method of destroying any cancer cells that remain after surgery and reduces the risk of breast cancer recurrence by 70 percent, according to Breastcancer.org. Radiation is delivered in multiple doses and in a variety of ways, depending on the severity of the cancer. The type you receive is determined by your doctor based upon your medical history.
External Beam Radiation
External beam radiation is the most common type of radiation used to treat breast cancer and is typically administered five days a week over a period of five to seven weeks on an outpatient basis. This regimen may change, however, depending on how well you respond to the therapy and the side effects you suffer from it. Using a linear accelerator, the doctor delivers high-energy beams of radiation directly to the site of the cancer. According to Breastcancer.org, he may start on the side of your breast and face the beam toward the center, or start in the center and move it toward the side. If your lymph nodes need to be treated as well, he may add more angles or treatment fields.
Interstitial Brachytherapy
Brachytherapy is internal radiation. Interstitial brachytherapy involves the implantation of flexible, hollow plastic catheters near the site of the tumor once the tumor has been removed through a surgical procedure known as a lumpectomy. These catheters are sewn into place, and over the course of a week, radioactive pellets are inserted into them. These catheters are then connected to a high-dose brachytherapy machine for approximately 15 minutes, two to three times a day. Depending on the dose, a hospital stay may be required, as you may be radioactive.
Intracavitary Brachytherapy
Intracavitary brachytherapy is another type of internal radiation; however, it is one that is performed on an outpatient basis. This type of radiation requires the insertion of a special tube with a balloon attached to the end. The insertion generally takes place once the tumor is removed from the breast, with the balloon positioned carefully in its place. Over a period of five days, radioactive seeds are placed in the center of the balloon through the end of the tube. Two treatments a day are given, lasting five to 10 minutes each, with balloon removal taking place on the last day of treatment.
Intensity-Modulated Radiation Therapy
Intensity-modulated radiation therapy (IMRT) is most commonly used to treat prostate, head and neck cancer; however, it has been used in the treatment of some breast cancers as well. According to RadiologyInfo.com, it is a more advanced form of radiation therapy that uses computer-controlled linear accelerators to deliver the radiation. Using a 3-D picture of the tumor allows the doctor to deliver more precise treatment at the most effective site. Higher doses can also be administered, and dosages may be adjusted during the session. This results in maximum treatment of the tumor while minimizing damage to the healthy tissue.
3-D Conformal Radiation Therapy
This type of radiation is similar to IMRT, according to UPMC Cancer Centers. By using a 3-D image of the tumor, doctors can deliver radiation that conforms to the tumor's exact size and shape. This allows for less damage to healthy tissue while increasing the rate of success for shrinking and destroying the tumor. Unlike in IMRT, the dose cannot be controlled during the session.
