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