About radiation therapy

Radiation therapy is a form of treatment that uses high-energy X-rays to destroy cancer cells. It can be used in several situations: after breast-conserving surgery, after a mastectomy or when cancer has spread to other parts of the body. Radiation therapy is used after surgery to kill remaining cancer cells and help prevent the cancer from coming back. It may also be used to provide relief from pain and other symptoms of metastatic breast cancer, which is cancer that has spread to other parts of the body.

Some of the many radiation therapies City of Hope offers include those listed below.

External beam radiation therapy (EBRT)

The most common type of radiation therapy for breast cancer is EBRT, which usually begins within six to eight weeks after surgery. EBRT, a fast, painless therapy performed as an outpatient procedure, is targeted to the area that was surgically treated, including the area of the breast where cancer was removed, and may be delivered to nearby lymph nodes. Some common EBRT methods used at City of Hope are:

Accelerated partial breast irradiation (APBI): APBI is a breast radiation therapy in which focused radiation is delivered to the part of the breast where the tumor was removed. It is appropriate for some patients with breast cancer who have already undergone a lumpectomy. This radiation is delivered at an accelerated rate, taking only five days, and allows radiation to be contained to the part of the breast surrounding the tumor cavity as much as possible. Because the radiation is so targeted, it tends to cause fewer and less severe short-term side effects (such as skin irritation, fatigue or breast tenderness) and a much lower risk of long-term negative effects on the healthy surrounding tissue, including the heart and lungs, when compared to whole breast irradiation or whole breast and lymph node irradiation.

Whole-breast radiation (with or without lymph node radiation): Patients who are not candidates for APBI most often undergo whole breast irradiation, which may or may not include radiation applied to the lymph nodes. This course of radiation is most commonly given over a period of three to four weeks. Some patients who receive whole breast irradiation may also be candidates for a total of only five treatments. These shorter courses of radiation have been shown to be as effective at preventing cancer recurrence in the same breast as radiation given over longer periods of time.

Postmastectomy radiation: Some women who undergo mastectomy benefit from radiation therapy to the chest and lymph node regions surrounding the surgical site. The most common reason we recommend radiation therapy after mastectomy is due to axillary lymph node involvement. These courses of radiation may be as short as three weeks but no more than five weeks, particularly for patients who have undergone breast reconstruction.

Prone breast radiation

Prone breast radiation is a special body position that patients may use during breast cancer treatment. Unlike traditional positioning, where the patient lies on her back, prone positioning has the patient lying face down with the breast suspended through a cutout in the treatment table. This approach allows for better radiation dose distribution to the target tissue and reduces radiation exposure to the heart, lungs, chest wall muscles and ribs. In patients with larger breasts, prone radiation reduces the risk of severe skin reactions compared to receiving radiation while lying face up. Prone radiation is an option for nearly all women undergoing APBI or whole breast irradiation without lymph nodes radiation.

Deep inspiration breath hold (DIBH)

In patients who are not candidates for prone radiation, DIBH is an alternative that may be used to significantly reduce radiation doses to the heart, lungs, liver and other normal tissues. With this technique, the patient is asked to hold her breath for 10-15 seconds at a time during inspiration, which pushes these organs further away from the breast and chest wall area. The radiation beam automatically turns off when the patient stops holding her breath. This technique is used for most patients receiving radiation in a supine position (on their back).

3-D conformal radiation therapy

3-D conformal radiation therapy is the most common type of EBRT used at City of Hope. It involves the radiation oncologist carefully defining the intended target for radiation and the surrounding normal tissues that may be at risk. Radiation fields are then designed to conform a radiation dose to the targets and reduce radiation to surrounding normal tissues and organs.

Intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT)

In some cases, 3-D conformal radiation therapy is not able to cover the intended radiation targets while reducing radiation doses to normal tissue. In these cases, IMRT and VMAT are used. These techniques use advanced software to sculpt radiation doses that match the cancerous targets while reducing radiation doses to normal tissues. Your doctor may recommend IMRT or VMAT if they determine it’s a better option than conventional EBRT.

Image-guided radiation therapy (IGRT)

In order to ensure that radiation treatments are delivered accurately, IGRT may be used to verify treatment positions before undergoing radiation. This may involve the use of X-rays or a CT scan.

Stereotactic body radiation therapy (SBRT)

In certain patients with metastatic breast cancer, SBRT may be used to deliver ablative doses of radiation to a tumor over a few sessions of around three to five treatments. SBRT uses many of the techniques above, including DIBH, IGRT and IMRT/VMAT, to safely deliver high doses of radiation while reducing the effects on normal tissues.