Radiation treatment is a medical procedure for killing or disabling cancer cells in the breast by using high-energy X-ray or proton beams. The radiation is delivered by one of two methods: a machine outside the body that directs a beam to the target area or by small catheters or pellets with radioisotopes that are placed inside the body. Because radiation can damage healthy cells in addition to killing cancerous ones, precautions are taken to focus the radioactive effects on the cancer. 

Radiation therapy has proven to be an effective means of treating breast cancer. Though this type of therapy can have side effects, they are typically milder than many people suppose. 

What Types of Radiation Treatment for Breast Cancer Are There?

As noted above, there are two primary forms of radiation treatment for breast cancer: external beam radiation therapy, or EBRT, and breast brachytherapy or internal radiation. There are variations on each of these technologies described below:

External Beam Radiation Therapy (EBRT)

• Hypofractionated Radiation Therapy: This is an accelerated form of radiotherapy, where large doses are delivered in a relatively compact timeframe – often five days a week for three weeks. This method is showing promise in treating women with breast-conserving surgery whose cancer has yet to spread to the underarm lymph nodes. 
• Three-dimensional Conformal Radiation Therapy (3D-CRT): With 3D-conformal radiotherapy, the external beam is precisely targeted by special machinery to irradiate only the tissue associated with the cancer (called the tumor bed). The patient is treated twice daily for five days. 
• Intensity-modulated Radiation Therapy (IMRT): IMRT combines 3D targeting technology with an ability to control the intensity or dosage strength of the radiation beams. This creates an additional safeguard for protecting healthy cells from misdirected radiation.
• Intraoperative Radiation Therapy (IORT): A single large dose of radiation is delivered to the patient following breast-conserving surgery, prior to closing the incision.

Breast Brachytherapy

• Interstitial Brachytherapy: Following surgery to remove the cancerous mass, the medical team inserts catheters inside the breast at the tumor’s original location. Radioactive pellets are placed inside these catheters for short periods of time, irradiating the surrounding tissues to kill any remaining cancerous cells.
• Intracavity Brachytherapy: This method of internal radiation is a recent innovation on interstitial brachytherapy. A medical device is placed inside the breast at the site of the cancer, after a surgical procedure. This device is designed to receive radioactive pellets by means of a catheter that can be accessed from outside the patient’s body. Treatment takes place twice a day for five days, after which the device is removed from the breast. 

When Is Radiation Therapy Used in Breast Cancer Treatment?

Radiation therapy is used to treat breast cancer in the following circumstances:

• Radiation after lumpectomy: A lumpectomy is the surgical removal of a breast tumor and the surrounding tissue. It is an important procedure in breast-conserving surgery (BCS). Radiation therapy is used in conjunction with surgery to kill any leftover cancer cells in the adjacent tissue, to reduce the possibility of the disease’s resurgence at a later date. 
• Radiation after mastectomy: A mastectomy is the surgical removal of the entire breast, due to the size of the tumor or the spreading nature of the cancer. Radiation is used to check the possible reappearance of cancer in the lymph nodes. 
• Radiation for locally advanced breast cancer: Some tumors cannot be removed by surgery. Radiation is a primary therapy in these situations. 
• Radiation for metastatic breast cancer: Radiation can also be used to shrink metastasizing tumors that are an ongoing source of pain. 
• Proton therapy: Proton-beam therapy replaces X-rays with protons as the radiation agent. Proton beams release energy in narrower intervals, which means that, in theory, they can be focused more completely on cancer cells than X-rays.

How Do I Prepare for Breast Cancer Radiation Therapy?

Radiation treatment requires preparation on the part of you and your medical team. That’s because radiation dosages must be precisely targeted to maximize their curative effect while minimizing damage to surrounding tissues. This is particularly critical with external-beam radiation. Planning may involve:

• Radiation simulation: During a simulation procedure, your physician will mark your body to improve positioning for the radiation session. If you’re undergoing brachytherapy, your medical team may also insert marker pellets in the tumor bed to guide introduction of the radioactive isotopes. 
• Planning scans: Your physician will take CT scans of your breast and chest cavity.

This preparatory work enables your physician to select the type and dosage of radiation best suited to treating your cancer.

What Are the Side Effects of Radiation Therapy for Breast Cancer?

Radiotherapy for breast cancer has a number of possible side effects:

• External beam radiation therapy (EBRT): External radiation treatments can lead to feelings of fatigue, swelling in the breast, and sunburn-like redness and peeling of the skin at the point of treatment. Long-term effects sometimes include changes in breast shape, difficulty breastfeeding, and numbness and pain in the shoulders, arms, hands, and chest. In very rare cases, another form of cancer, known as angiosarcoma, can result. 
• Breast brachytherapy: Internal radiation treatments can cause pain, infection, bruising, sunburn-like symptoms, and pooling of fluid in the breast. Both internal and external radiotherapy treatments have been occasionally linked to a decline in the structural integrity of the rib bones.

What Happens After I Complete Radiation Therapy for Breast Cancer?

You’ll see your physician regularly after completing radiation therapy for breast cancer. He or she will evaluate the effectiveness of your treatment. This process will continue indefinitely, to ensure that you remain cancer-free. If the treatment is unsuccessful or your cancer returns, your physician will devise a new plan for addressing it.