Radiation Therapy for Breast Cancer

What is radiation therapy for breast cancer?

Radiation therapy, also known as radiotherapy, is a treatment that uses high-energy radiation to kill cancer cells and shrink tumours. Radiation therapy for breast cancer targets:

• The breast area
• The lymph nodes (in the armpits)
• Other parts of the body if the cancer has spread

Types of radiation therapy for breast cancer

Depending on the location and size of your breast tumour, your doctor will recommend the most appropriate type of radiation therapy for you:

External beam radiation

This is the most common type of radiation therapy for women with breast cancer. During this procedure, a large machine called a linear accelerator delivers radiation beams to the treatment area from different directions.

Note: Proton beam therapy is a new type of radiation therapy that uses proton particles rather than X-rays to treat cancer.

Internal radiation (Brachytherapy)

Brachytherapy is a newer form of radiation therapy. It injects radioactive cancer-killing substances into the treatment area after the tumour has been surgically removed.

Intraoperative radiation therapy (IORT)

IORT is a less common type of partial-breast radiation, where the entire course of radiation is delivered in a single dose to the cancerous area. If you had a lumpectomy (removal of a tumour from the breast), this procedure takes place in the operating room. Your surgeon will perform IORT before closing your surgical site.

When do you need radiation therapy for breast cancer?

Radiation therapy may be used to treat breast cancer at almost every stage. It is typically used:

• After a lumpectomy (breast tumour removal) to lower the risk of cancer recurring in your breast.
• After a mastectomy (complete breast removal), especially if the:
  • Tumour was larger than 5 cm
  • Cancer has spread to your lymph nodes
  • Cancer cannot be removed completely (tissue margins are positive for cancer cells)
• To treat cancer spread (metastasis) and ease side effects.

Sometimes, radiation therapy is used in place of surgery to shrink a tumour. Your doctor may recommend this treatment if your tumour cannot be surgically removed (unresectable) due to its size or location, or you are unsuitable for surgery.

Depending on your type of breast cancer and cancer stage, radiation therapy may be used together with other cancer treatments like surgery and chemotherapy.

Who should not undergo radiation therapy for breast cancer?

Radiation therapy may not be suitable for you if:

• You are expecting.
• You have a connective tissue disease, such as scleroderma, which makes you extra-sensitive to the side effects of radiation.
• You are unable to commit to the daily schedule of radiation therapy.

What are the risks and complications of radiation therapy for breast cancer?

Radiation therapy may also cause or increase your risk of:

• Swollen arms (lymphedema), if the treatment targets the lymph nodes under your arm.
• Complications from an implant (if you had breast reconstruction with an implant after a mastectomy). The reconstructed breast may interfere with radiation therapy reaching the area affected by cancer.

In rare cases, radiation therapy may cause or increase the risk of:

• Lung tissue inflammation or heart damage
• Rib fracture or tenderness on your chest wall
• Secondary cancers, such as bone or muscle cancers (sarcomas), or lung cancer

How do you prepare for radiation therapy for breast cancer?

Before your treatment starts, your doctor will meet with you to:

• Review your medical history
• Do a physical examination
• Discuss the potential benefits and side effects of your radiation therapy

What can you expect in radiation therapy for breast cancer?

Depending on the type of radiation therapy you will receive, your preparation procedure, treatment schedule and radiation delivery method will differ.

Radiation therapy is usually done on an outpatient basis at a hospital or treatment facility. It usually begins:

• 3 – 8 weeks after surgery
• 3 – 4 weeks after chemotherapy has been completed

Note: During radiation therapy, you should avoid taking certain supplements (such as vitamins A, C, D, and E) as they may interfere with the radiation's ability to destroy cancer cells. You should also avoid exposure to the sun, as the treated skin may be more sensitive

Estimated duration

Your doctor may either recommend one of the following treatment schedules (courses):

• Typical course. Involves 1 radiation treatment a day, 5 days a week (usually from Monday to Friday), for 5 – 6 weeks. Each radiation treatment takes around 15 – 45 minutes.
• Hypofractionated (shortened) treatment. Involves 2 radiation treatments a day. This usually lasts 1 – 4 weeks for whole-breast irradiation or 5 days for partial-breast irradiation.

External beam radiation therapy

Before starting external beam radiation therapy, your doctor and radiation oncology team will go through a radiation therapy planning session (simulation) with you, where your breast area is carefully mapped to target the precise location of your treatment.

During the simulation, you will:

• Be positioned in the best way to target the affected area and avoid damage to surrounding normal tissue. Sometimes pads or other devices are used to help you hold the position.
• Undergo a computerised tomography (CT) scan to locate the treatment area and to identify the normal tissues to avoid.
• Be marked with semi-permanent ink or tiny tattoo dots, as a guide for the radiation therapist when administering the radiation
• Have the radiation treatment and dosage planned out for you by the radiation oncology team

You will be ready to start treatment once the simulation, planning and quality assurance checks are completed.

During the procedure, you will:

• Change into a hospital gown.
• Get into the position you were in during the simulation process.
• Have images or X-rays taken to ensure that you are correctly positioned.
• Be left alone in the treatment room as the machine delivers the radiation.
• Be monitored by your doctor or the staff from another room on a television screen. You should be able to communicate with them via an intercom. Let your doctor or staff know if you feel sick or uncomfortable.
• Not experience any pain but may feel some discomfort from lying in the required position.

After the procedure, your doctor may recommend a radiation boost even after the main radiation therapy sessions have been completed.

Internal radiation therapy (Brachytherapy)

Before starting internal radiation therapy, your doctor will place an implantable device inside your breast at the time of the surgery or in a separate procedure.

This device will carry the targeted radiation to the tissue where the cancer originally grew (also known as the tumour bed).

During the procedure, the radioactive source — usually a radioactive substance sealed in seeds or tiny tubes — is inserted for a few minutes in the implanted radiation delivery device each time.

After the procedure, you may feel some soreness or tenderness in the affected area as the tissue recovers from the surgery and radiation. Your doctor will prescribe some pain medication for it.

After the entire course of treatment is completed, your doctor will remove the radiation delivery device.

Care and recovery after radiation therapy for breast cancer

Common side effects of radiation therapy for breast cancer include fatigue, skin irritation such as itchiness or redness, and breast swelling. You can minimise common side effects by:

• Wearing loose-fitting cotton clothes as bras and tight clothing may rub or irritate your skin.
• Treating your skin gently and checking with your doctor before using any deodorants, lotions, or creams on the treated area.
• Taking good care of yourself by eating well and getting adequate rest.
• Staying active, as regular exercise can help to reduce the fatigue associated with radiation therapy.

Most of the side effects should go away within a few months of your last treatment session. Call your doctor if you experience persistent side effects or any of the following:

• Chest pain
• Severe skin or breast inflammation
• Signs of infection, such as fever, chills or weeping skin wounds

Long-term side effects

Discuss with your doctor the long-term side effects that may occur, such as:

• Changes in breast size (smaller or larger) and sensitivity.
• Lymphedema (swelling) of the breast or arm.
• Skin changes, such as red, dry, tender or itchy skin. Some individuals with fair skin may have a slightly pink or tan appearance years after their treatment ends.
• Tiny blood vessels (telangiectasias) in the radiated area that look like fine red threads. In general, this is not a cause for concern.

Your doctor may have suggestions or ways to help you manage these issues.