Radiation Therapy for the Treatment of Breast Cancer

Radiation therapy (or radiotherapy) uses high-energy rays to stop cancer cells from growing and dividing. Radiation therapy is often used to destroy any remaining breast cancer cells in the breast, chest wall, or axilla (underarm) area after surgery. Occasionally, radiation therapy is used before surgery to shrink the size of a tumor. A common treatment for early stage breast cancer is breast-conserving therapy. Breast-conserving therapy (BCT) is the surgical removal of a breast lump (lumpectomy) and a surrounding margin of normal breast tissue. BCT is typically followed by at least six to seven weeks of radiation therapy. Treatment with radiation usually begins one month after surgery, allowing the breast tissue adequate time to heal. Radiation therapy may occasionally be recommended for women to destroy remaining cancer cells after mastectomy (surgical removal of the affected breast) or to shrink tumors in patients with advanced breast cancer.

Main Menu

• External Beam Radiation
• Internal Beam Radiation
• Intra-Operative Radiation
• Dose Verification System

External Beam Radiation

The most common type of radiation therapy used on women with breast cancer is called external beam radiation. External beam radiation is delivered from a source outside the body on the specific area of the body that has been affected by the cancer. Experts compare the experience of external beam radiation to having a diagnostic x-ray, except that radiation is usually administered for a longer period of time and at a higher dose.

Before radiation therapy begins, the physician will measure the correct angles for aiming the radiation beam at the specific area of the body and make ink marks on the patient’s skin. As part of treatment after breast surgery, patients are typically treated with radiation five times per week for at least six weeks in an outpatient clinical setting. Each treatment generally lasts a few minutes; the entire radiation session after machine set-up typically lasts 15 to 30 minutes. The procedure itself is pain-free. While the radiation is being administered, the technologist will leave the room and monitor the patient on a closed-circuit television. However, patients should be able to communicate with the technologist at any time over an intercom system. Click here to learn more about what to expect during a radiation session.

Side effects of external beam therapy vary among patients. The most common side effect is fatigue. Fatigue (extreme tiredness) can be especially bothersome in the later weeks of treatment. Patients who experience fatigue after radiation sessions should get plenty of rest and try to maintain an active lifestyle. While many patients can still work and participate in normal activities during radiation therapy, some patients find it necessary to limit their work or activities until treatment has been completed.

Other common side effects of radiation therapy are neutropenia (sharp decrease in white blood cell count) swelling of the breast, a feeling of heaviness in the breast, a sunburn-type appearance of the breast skin, and loss of appetite. These side effects usually disappear after six to 12 months. Near the end of treatment with radiation, the breast skin may become moist. Patients should try to wearing loose fitting clothing and expose the skin to air as much as possible to help the skin heal quickly.

In most cases, the breast will look and feel the same after radiation therapy is completed, though it may be more firm. In rare cases, radiation therapy may cause changes in the breast size. Breasts may become larger due to fluid build-up (seroma) or smaller due to tissue changes. Some women may find that the breast skin is more sensitive after radiation, while others may find that it is less sensitive. Radiation therapy of the axillary (underarm) lymph nodes may cause lymphedema (chronic swelling of the arm) in some women. Women who have radiation to the lymph nodes will usually be instructed on arm exercises and other activities to help prevent lymphedema. Pregnant women are usually advised not to undergo radiation therapy because of possible harm to the fetus. Click here for more information on breast cancer and pregnancy.

The following recommendations may help reduce pain from skin reactions to radiation therapy:

• Avoid any additional sun exposure to the area
• Wear loose-fitting clothing, preferably cotton or other material that "breathes"
• Use warm or tepid water when bathing, rather than hot water
• Avoid constricting bras (if a bra must be worn at all)
• Use cool compresses (not cold or ice packs, as that may cause additional skin damage)
• Lotions or powders on the treated area are generally not recommended
• Specific creams should be approved by the radiation oncologist or his/her nurse. Often, there should not be any substance on the skin that could affect the radiation treatment or lead to a more serious burn injury (such as oil).

Patients should talk to their physicians about soothing oils or creams that may be allowed between (not during) treatment sessions.

Internal Radiation

Brachytherapy (also called internal radiation) is an experimental method currently being developed to use on breast cancer patients. Instead of using radiation beams from outside the body, radioactive substances are placed directly into the breast tissue next to the cancer. Brachytherapy involves the surgical placement of 10 to 20 plastic catheters (tiny tubes called implants) into the breast tissue next to the tumor to help guide the radioactive materials to the correct area of the body. Technologists then insert pellets of radioactive substances (called Iridium-192) into the catheters. Nine or more times over the course of a week, the catheters are briefly connected to a high-dose-rate brachytherapy machine for internal radiation treatment. The treatments usually take about 10 minutes each and are painless. The tubes are usually removed after a week.

Brachytherapy is not standard practice for breast cancer patients but is currently used on cancers in other areas of the body such as the mouth, cervix, or prostate.

Possible advantages of brachytherapy:

• The reduction of time a patient has to undergo radiation therapy from at least six weeks to one week.
• Less irritation of healthy breast tissues.
• Patients who must also undergo chemotherapy as part of their breast cancer treatment do not have to delay treatment for as much time.
• Fewer skin reactions, such as redness, rashes, or irritations

Physicians are unsure whether brachytherapy is as effective in destroying breast cancer cells as external beam radiation therapy. Several clinical trials are currently being run to evaluate the safety and effectiveness of brachytherapy. Side effects of brachytherapy include risk of infection and breast swelling.

Dose Verification System

The dose verification system (DVS), which is manufactured by Sicel Technologies, has been approved by the U.S. Food and Drug Administration (FDA) for radiation treatment of breast and prostate cancer in 2006. DVS helps radiologists determine the amount of radiation a patient receives is within the prescribed range each time radiation treatments are administered. To do so, the radiologist can use the system measures the amount of radiation that is delivered to the tumor tissue, tumor bed, or healthy tissue. DVS differs from normal radiation therapy in that the physician must implant DVS radiation dosimeters near the tumor or tumor bed and/or surrounding normal tissue during a minimally invasive procedure. Most patients receive one or two dosimeters. Once implanted, wireless technology transmits the information to a hand-held monitor and radiation absorption rates are read during daily treatments, enabling radiologists to verify that the dose received by the patient is within the prescribed range. The dosimeter does not produce radiation itself.

The DVS implantable dosimeter is 0.8 inches (20mm) long and 0.08 inches (2.1mm) in diameter. During radiation treatment, each dosimeter transmits the amount of radiation that is received at its location. The dosimeter near the tumor should receive the highest dose, while the other receives a lower dose. After radiation treatment sessions are completed, the dosimeters will remain inside the patient without an effect on a patient's daily routine.

In January 2008, the U.S. Centers for Medicare and Medicaid created a new HCPCS code (Healthcare Common Procedure Coding System) for the DVS. The code will cover the cost for the Dose Verification System (DVS). The code, which reimburses radiation therapy centers for the medical device when implanted in any body site, makes DVS more accessible to patients undergoing radiation treatment for breast and prostate cancer because private insurers will cover the cost for the device. The cost for the device is also adequately covered by the new code for Medicare patients treated in freestanding centers. Separate codes are available to cover the cost associated with implanting the device.

The patient's physician will determine whether she is a candidate for DVS. Some patients have experienced discomfort after the implantation of the DVS dosimeters; however, according to Sicel Technologies, no adverse long-term effects have been reported.

Additional Resources and References

• To learn more about radiation therapy for cancer treatment, please visit http://www.imaginis.com/radiotherapy/
• The American Cancer Society provides information on radiation therapy for breast cancer at http://www.cancer.org/
• The National Cancer Institute provides information on radiation therapy for breast cancer at http://www.cancer.gov/
• Cancer Treatment Centers of America (CTCA) provides information on breast brachytherapy at http://www.brachytherapy.com/breast-brachy.html.
• To learn more about DVS, please visit http://www.imaginis.com/breasthealth/news/news6.08.08.asp
• Visit the diagnosis and treatment section of the Imaginis.com breast health bookstore for additional resources: http://www.imaginis.com/bookstore/breasthealth/diagnosis.asp

Updated: October 18, 2009