Lung cancer

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Radiation therapy for non–small cell lung cancer

Radiation therapy uses high-energy rays or particles to destroy cancer cells. Most people with non–small cell lung cancer have radiation therapy. Your healthcare team will consider your personal needs to plan the type and amount of radiation, and when and how it is given. You may also receive other treatments.

Radiation therapy is usually combined with chemotherapy to treat non–small cell lung cancer. This is called chemoradiation. The 2 treatments are given during the same time period.

Radiation therapy is given for different reasons. You may have chemoradiation or radiation therapy:

  • as the main treatment for non–small cell lung cancer that can’t be removed with surgery, or if you don’t want to have surgery
  • after surgery to lower the risk of the cancer coming back (recurring) (called adjuvant therapy)
  • to relieve pain or control the symptoms of advanced non–small cell lung cancer (called palliative therapy)

People with stage 1 or 2 non–small cell lung cancer that has been completely removed with surgery are not offered radiation therapy after surgery. This is because research has shown that it reduces survival instead of improving it.

The following types of radiation therapy are most commonly used to treat non–small cell lung cancer.

External beam radiation therapy

During external beam radiation therapy, a machine directs radiation through the skin to the tumour and some of the tissue around it. Modern radiation techniques have improved how well radiation therapy works as a treatment for non–small cell lung cancer.

Before radiation therapy is started, your treatment is planned carefully. The radiation healthcare team measures how your lungs move when you breathe and maps the shape of your internal organs. This helps the radiation team to plan the best way of giving you external beam radiation therapy. The goal is to aim the radiation at the tumour while lowering the amount of radiation to surrounding tissue.

External beam radiation therapy is usually given 5 days a week, for 5 to 7 weeks. If it is being used as palliative radiation therapy, it may not be given for as long.

There are several different ways to give external beam radiation therapy for non–small cell lung cancer.

3-D conformal radiation therapy (3-D CRT)

The most common form of external beam radiation therapy is 3-D CRT. A CT scan is used to guide the radiation beams to the tumour. The radiation beams are aimed from several different directions at the tumour. The radiation beams are all the same strength.

Intensity-modulated radiation therapy (IMRT)

IMRT is a much more targeted way of giving radiation therapy than 3-D CRT. The radiation beams are given in small beams that are shaped by a machine called a multi-leaf collimator. The strength of the beams is different across the treatment area so the tumour gets the most radiation and nearby tissue gets less. IMRT is often used if the treatment area includes important areas of the body such as the spinal cord.

Stereotactic body radiotherapy (SBRT)

SBRT is a way of giving radiation therapy from several different positions around the body. A CT scan is used to place tiny gold seeds or coils (called fiducials) into the tumour. These seeds are used as a guide to direct the radiation therapy to the tumour. The directed radiation beams all meet at a point in the tumour. This is a very accurate way of giving radiation because the tumour gets a high dose of radiation while the surrounding tissue gets lower doses. SBRT is sometimes called stereotactic ablative radiotherapy (SABR).

SBRT for non–small cell lung cancer is given over 7 to 10 days, which is much shorter than other ways of giving radiation therapy.

SBRT may be offered to people with lung cancer that hasn’t spread outside of the lung, when surgery can’t be done because of a person’s health, or to people who don’t want to have surgery.

Hypofractionated radiation therapy

With hypofractionated radiation therapy, fewer radiation treatments are given. This is done by giving either a short course of daily treatments or by giving fewer large doses (sometimes just a single treatment).

Hypofractionated radiation therapy may be offered to people with non–small cell lung cancer who are not able to have the high doses of radiation given during SBRT.


Brachytherapy is internal radiation therapy. It uses a radioactive material called a radioactive isotope. It is placed right into the tumour or very close to it. Radioactive materials can also be placed in the area from where the tumour was removed. The radiation kills the cancer cells over time.

Brachytherapy may be used to treat a non–small cell lung cancer tumour that is blocking the large airways of the lung. The doctor places the radioactive isotope into the airways during a bronchoscopy (endobronchial radiation therapy).

Brachytherapy may be used as a primary treatment for people who cannot have external beam radiation therapy because of poor lung function.

Side effects

Side effects can happen with any type of treatment for non–small cell lung cancer, but everyone’s experience is different. Some people have many side effects. Other people have few or none at all.

During radiation therapy, the healthcare team protects healthy cells in the treatment area as much as possible. But damage to healthy cells can happen and may cause side effects. If you develop side effects, they can happen any time during, immediately after or a few days or weeks after radiation therapy. Sometimes late side effects develop months or years after radiation therapy. Most side effects go away on their own or can be treated, but some side effects may last a long time or become permanent.

Side effects of radiation therapy will depend mainly on the size of the area being treated, the specific area or organs being treated, the total dose of radiation, the treatment schedule and whether or not radiation therapy is being given with chemotherapy. Some common side effects of radiation therapy used for non–small cell lung cancer are:

Tell your healthcare team if you have these side effects or others you think might be from radiation therapy. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them.

Questions to ask about radiation therapy

Find out more about radiation therapy and side effects of radiation therapy. To make the decisions that are right for you, ask your healthcare team questions about radiation therapy.


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