Radiation may be given before surgery to shrink the tumor (neoadjuvant therapy), or after surgery to keep the cancer from growing back (adjuvant therapy). The latest techniques limit the amount of radiation a patient receives and target the exact location of the tumor, keeping other areas of the body radiation-free.
External Beam Radiation Therapy involves a series of daily outpatient treatments to accurately deliver radiation to the breast. Painless radiation treatments are delivered in a series of daily sessions. Each treatment will last less than 30 minutes, Monday through Friday, for five to seven weeks. The usual course of radiation treats only the breast, although treatment of the lymph nodes around the collarbone or the underarm area is sometimes needed.
3-dimensional conformal radiotherapy (3D-CRT) combines multiple radiation treatment fields to deliver very precise doses of radiation to the breast and spare surrounding normal tissue.
Intensity modulated radiation therapy (IMRT) is a form of 3D-CRT that further modifies the radiation by varying the intensity of the radiation beams. It is currently being studied for treating breast cancer. Side effects might include skin irritation, like a mild to moderate sunburn, mild to moderate breast swelling and fatigue.
Partial Breast Irradiation Doctors are studying ways to deliver radiation to only part of the breas Available in a few clinics for a very select group of patients, these techniques are used after a lumpectomy to deliver radiation to the tumor site rather than the entire breast.
Breast brachytherapy involves placing flexible plastic tubes called catheters or a balloon into the breast. Over one to five days, the catheters or the balloon are connected to a brachytherapy machine so high doses of radiation can treat the nearby breast tissue.
Other techniques include
Intraoperative radiation therapy (IORT) gives a single large dose of radiation in the operating room right after breast-conserving surgery for women with early stage cancer.
3D-conformal radiotherapy In this technique, the radiation is aimed directly at the site of the tumor, sparing healthy breast tissue. Treatments are given twice daily for five days. Because only part of the breast is treated, this is considered to be a form of accelerated partial breast irradiation.
After Mastectomy Radiation In cases where the breast is surgically removed, your doctor may suggest radiation therapy for the chest wall and nearby lymph node areas. Whether or not radiation therapy should be used after removal of the breast depends on several factors, including the number of lymph nodes involved, tumor size and surgical margins.
More information can be found here: http://cancer.columbia.edu/radiation-oncology