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Breast Cancer: Radiation Therapy

What is radiation therapy?

Radiation therapy (or radiotherapy (RT) is a method for treating cancer that uses high-energy X-rays to kill cancer cells or try to prevent future cancer growth.. A machine called a linear accelerator is used to target radiation beams at the tumor or area at risk for disease while avoiding nearby normal tissues.

When might radiation therapy be used for breast cancer?

Radiation is used as a component of breast cancer treatment in several different scenarios. For example:

  • After you undergo surgery for breast cancer: Radiation is frequently used to consolidate the effect of breast cancer surgery. This is called adjuvant radiation treatment. Radiation may be recommended regardless of the type and extent of surgery you receive. It is often used after breast-conserving surgery (or lumpectomy) but may also be used after mastectomy. The “target” in the case of adjuvant radiation is microscopic cancer cells that cannot be seen on an exam or imaging but may remain behind after surgery. Adjuvant radiation for breast cancer is used to reduce the chances that the cancer will come back in the breast/chest or lymph node regions.

  • For metastatic breast cancer: In cases where breast cancer has spread to other sites in the body, radiation may be used as a palliative treatment. Palliative radiation addresses symptoms due to tumor involvement, such as pain, and is used to ease or eliminate these symptoms.

Which types of radiation therapy are used to treat breast cancer?

  • External beam radiation therapy (EBRT): EBRT is the most common type of radiation used to treat breast cancer. In this setting, the patient lies on a treatment table while a radiation machine (linear accelerator) is positioned to target the radiation beams at the breast/chest region. The radiation beam is very precisely shaped to aim at the target area while avoiding exposure to adjacent normal tissues. A team of specially trained technicians called radiation therapists positions the patient on the treatment table and runs the machine using intricate computer algorithms to deliver the radiation treatment. EBRT is usually given every day, Monday through Friday, for a series of consecutive weeks (as few as one week to as many as seven weeks). The patient is often on the treatment table for 15 to 20 minutes each day of treatment. EBRT is “painless” to receive; it feels just like getting a normal X-ray.

What happens before radiation therapy starts?

Before starting radiation therapy, a treatment planning session must be held. This session is called simulation. During simulation, your doctor will determine the optimal position for you to be in for treatment, and a device may be fashioned to help support you in that treatment position. Once you are in the correct position, a quick computed tomography (CT) scan of the chest is performed to obtain images of your anatomy in that treatment position. This scan allows your doctor to not only identify the radiation target(s) but also understand where adjacent tissues are located that should be shielded from the radiation. Once these images are obtained and reviewed by your doctor, a set of permanent ink dots (or tattoos) will be placed on your skin to mark how you should be set up on the treatment machine for each day of treatment.

What should I expect during radiation therapy?

Radiation treatment usually starts once you have recovered from surgery (or from chemotherapy, if needed). This recovery time can be as little as three weeks or as much as six to eight weeks, depending on the clinical scenario. EBRT is usually given once a day, five days a week, for a set number of weeks. In select cases, you may receive radiation twice a day over a shorter period of time.

For patients, radiation treatment is a lot like getting an X-ray for diagnostic purposes. Quite often, you will be asked to lie on your back (though some patients lie on their stomach for radiation). Treatment does not hurt, and the radiation machine does not touch you during treatment. While you are usually on the treatment table for 15 to 20 minutes, some treatment sessions can last longer, particularly on the first day of treatment. For most of the time that you are on the treatment table, the radiation therapists are carefully ensuring that you are in the correct position and lined up to the tattoos that you received during simulation.

Before the radiation beam is turned on, the therapists will briefly leave the room. During this time, they can see you, hear you and talk to you. Additional imaging may be performed before the actual radiation starts. The therapists will remind you to remain very still when imaging is being performed or when radiation is being delivered.

At least once a week, you will meet with your radiation oncologist. During this visit, you are encouraged to ask questions or share your concerns. Your doctor will take this time to assess whether you are experiencing side effects from treatment and address these issues as needed.

What are the side effects of radiation therapy?

While undergoing EBRT for breast cancer, you do not need to worry about being radioactive or exposing others to radiation. It is perfectly safe to be around people, including pregnant women and children.

All cancer treatments have side effects, but the type and severity of these side effects vary from person to person. Side effects from EBRT are often delayed at the onset of treatment, develop gradually and are cumulative in nature (i.e., they increase as the treatment continues). Most side effects can be managed or minimized, and short-term side effects should resolve within a few weeks of completing your treatment. Common short-term side effects of radiation therapy to the breast, chest and/or lymph nodes include the following:

  • Skin redness and irritation in the area treated

  • Skin darkening and dryness in the area treated

  • Tiredness

  • Tightness of the irradiated tissues

  • Temporary hair loss in the area treated

  • Occasional aches and pains in the area treated

In most cases, the effects of radiation on the skin are short term. The skin will heal after treatment ends. In some cases, the following long-term side effects may occur:

  • Occasional discomfort and sensitivity in the treated area

  • Mild to moderate increased firmness or tightness of the irradiated tissues

  • Mild swelling of the irradiated tissues

Other possible long-term side effects of radiation can occur. These side effects are very rare and depend on the dose and type of radiation used. Side effects may not show up until many years after you finish treatment. Ask your doctor about possible side effects and how to manage them.

What should I discuss with my health care provider?

Before deciding to have radiation treatment, talk with your health care provider about the following issues:

  • The location of the facility where radiation is given and your ability to get to it every day for the duration of your therapy

  • Whether you've had radiation treatment to your chest in the past

  • Whether you plan to have breast reconstruction in the future

  • Any other health conditions you have that may prevent you from getting radiation

Ask your health care provider to tell you about the benefits and risks of radiation therapy before making a decision.

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