Also called radiotherapy, radiation treatment directs high-energy x-rays at the cancer cells to kill them or to keep them from growing. Your treatment plan may include radiation therapy after surgery in order to kill any remaining cancer cells in the breast, chest wall or lymph nodes.
Women who undergo lumpectomy almost always need radiotherapy, too. Women who undergo mastectomy may also need radiotherapy, especially if their cancer involves lymph nodes or is larger in size (>5 cm).
Radiotherapy for breast cancer may involve:
- External Beam Radiation Therapy (EBRT): A machine outside the body delivers radiation to the entire breast with an extra dose or boost given to the tumor site. This is commonly given after a lumpectomy.
- Brachytherapy: A form of internal radiation therapy, this treatment places tiny radioactive wires, catheters or seeds within the body, in or near the tumor site.
Radiotherapy following Lumpectomy
- Whole Breast Irradiation: Usually all of the breast tissue is targeted with radiation. At Roswell Park, we use a shorter, 3-week radiation course instead of the traditional / standard 5 to 6 weeks. Short-course or hypofractionated whole breast irradiation provides a slightly higher dose of radiation per treatment, but with fewer treatments. This approach offers outcomes equal to standard radiation, while patients have the convenience of fewer visits.
- Accelerated Partial Breast Irradiation: This therapy delivers radiation only to the lumpectomy site, the most common place for breast cancer to recur. Roswell Park provides partial breast irradiation in various ways, including EBRT and brachytherapy. This approach is appropriate for some women with early-stage breast cancer (small tumors and confirmation of no evidence of cancer in the lymph nodes) and low-risk features.
- Tumor Bed Boost: This is another form of treatment targeting the lumpectomy site, providing additional radiation at the most common site of recurrence within the breast itself. It is given over 1 to 1.5 weeks after completion of whole breast irradiation.
Radiotherapy following Mastectomy
- Post-Mastectomy Radiation Therapy (PMRT): Following a mastectomy, some women are at risk for microscopic amounts of residual cancer left behind. These cells can be in the chest wall, the area where lymph nodes were removed, or other at-risk lymph nodes not removed during surgery. For patients at high risk for recurrence — those with large tumors, cancer in multiple lymph nodes, or other risk factors — radiation to the chest wall or reconstructed breast, plus the at-risk lymph node areas, is recommended. This treatment typically lasts 5 to 6 weeks.
Radiation Treatment Techniques to Reduce Side Effects
- Respiratory Gating: This technique, also called Deep Inspiration Breath Hold (DIBH), is used to reduce the risk of injury to the heart when radiation is being delivered to the left breast. When patients take a deep breath, the lungs are filled with air and this pushes the heart away from the breast when radiation is being delivered. Once they exhale, the machine automatically shuts off the radiation. A patient only has to hold their breath for 10 to 15 seconds at a time, and treatment is usually completed in a few breaths. The volume and depth of inspiration is practiced during the treatment planning session, and adjusted to each patient’s ability.
- Prone Positioning: Patients are treated lying on their stomach (instead of on their back like most radiation treatments). Radiation is directed at the affected breast, which hangs through an opening in the table. The unaffected breast does not hang through the table and is gently pulled to the side. This approach allows the breast to be targeted with reduced exposure to nearby organs, such as the lungs and the heart.
- Electronic Compensation: During treatment planning, your physician works with a member of the Radiation team, called a Medical Dosimetrist, who uses a computer program to create a customized radiation dose plan. Some areas of the breast or chest wall may receive more or less radiation due to the uneven shape of the breast or chest wall. Electronic compensation accounts for the unique shape of an individual patient and the area(s) being radiated. This results in a more even dose distribution, and minimizes so-called hot-spots or cold-spots within the radiation field.