What is radiotherapy?

Radiotherapy uses high-energy x-rays to destroy cancer cells, while doing as little harm as possible to normal cells.

Radiotherapy for non-small cell lung cancer (NSCLC) may be given:

  • on its own instead of surgery, to try to cure early-stage NSCLC
  • after surgery, to reduce the risk of cancer coming back (adjuvant radiotherapy)
  • at the same time as chemotherapy, if the cancer is locally advanced (concurrent chemoradiation)
  • before or after chemotherapy, if the cancer is locally advanced (sequential chemoradiation)
  • to control symptoms, if lung cancer has spread to other parts of the body (palliative radiotherapy).

Having external-beam radiotherapy for NSCLC

Before you start your treatment, it needs to be planned carefully by your radiotherapy team. This is to make sure the radiotherapy is aimed precisely at the cancer, causing as little damage as possible to surrounding tissue. We have more information about what to expect at your planning appointment.

You have the treatment in the hospital radiotherapy department. Usually radiotherapy is directly aimed at the lung from a radiotherapy machine. This is called external beam radiotherapy.

You usually have a course of radiotherapy for 4 to 7 weeks. Each treatment lasts for a few minutes. You usually have treatment every day from Monday to Friday, with a rest at weekends. Your doctor or nurse will tell you how many treatments you will have.

Some people might have radiotherapy over different times or in different ways. People with NSCLC may have radiotherapy three times a day over a shorter number of weeks. This is called CHART radiotherapy. If you have radiotherapy to control symptoms, you have it over a shorter course of treatment.

Rarely, if the cancer is blocking an airway, some people have radiotherapy given from inside the body. This is called internal radiotherapy or brachytherapy (see below).

Treatment sessions

At the beginning of each session of radiotherapy, the radiographer positions you carefully on the couch and makes sure you are comfortable. Radiotherapy is not painful, but you have to lie still for a few minutes during the treatment. You are alone in the room during treatment. But you can talk to the radiographer, who is watching from the next room.

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Continuous hyper-fractionated accelerated radiotherapy (CHART) for NSCLC

Continuous hyper-fractionated accelerated radiotherapy (CHART) is a way of giving radiotherapy.

Instead of one session of radiotherapy a day, you have 3 sessions. You have them every day, including weekends, for 12 days. Each treatment must be at least 6 hours apart. You usually have to stay in the hospital or somewhere nearby during treatment.

CHART may work better than standard radiotherapy for some people with NSCLC. It may be a possible treatment if you have:

  • stage 1 or 2 NSCLC and surgery is not possible
  • stage 3 NSCLC and you are not well enough to have chemoradiation.

Your doctor can tell you if CHART is suitable for you. It is not available at every hospital, so you may have to travel further to have it.

Stereotactic radiotherapy (SABR) for NSCLC

Stereotactic ablative radiotherapy (SABR) is a specialised type of radiotherapy. Doctors use scans and specialist machinery to make the radiotherapy beams more precise. This means they can reach small cancers with a high dose of radiotherapy, and only give a low dose to healthy tissue around the tumour. This helps reduce side effects.

People with NSCLC that is small may have SABR instead of surgery. It is only suitable for some people. It is not available at every hospital, so you may have to travel further to have it.

People usually have SABR over less time than standard external radiotherapy. For example, they might have 3, 5 or 8 treatments over 2 weeks.

We have more information about stereotactic radiotherapy.

Palliative radiotherapy

Sometimes people have external radiotherapy to shrink the cancer and improve their symptoms. It can help them feel better so they can do more. This is called palliative radiotherapy. It is usually given when the cancer:

  • is advanced in the lung
  • has spread to other parts of the body.

It may be given to improve:

  • breathlessness
  • chest pain
  • a cough
  • coughing up blood.

Some people have just one session of treatment. Other people have it over a few days. Or they might have a higher dose over one or two weeks. Your cancer doctor or nurse will explain more about this.

Doctors may use radiotherapy to treat superior vena cava obstruction. This is when the cancer is pressing on a vein in the chest and blocking the blood-flow.

People can also have palliative radiotherapy to relieve pain if the cancer has spread to areas such as the bones. They can usually have this over one or two treatments.

Internal radiotherapy

Internal radiotherapy is when doctors place radioactive material inside the body next to the cancer.

If the cancer is blocking one of the airways, you may have a type of internal radiotherapy (brachytherapy).

Most people have only one session of treatment. It is usually done in an operating theatre. The doctor passes a thin tube (catheter) down the nose or throat into the lung, using a bronchoscope. They put a small piece of radioactive material inside the catheter, next to the cancer. They leave it in place for a few minutes to give a dose of radiation to the cancer. Then they remove it together with the catheter.

We have more information about internal radiotherapy.

Possible side effects of radiotherapy for lung cancer

You may get some side effects over the course of your treatment. Your doctor, nurse or radiographer will talk to you about this so you know what to expect.

They will give you advice on managing side effects. Always tell them about any side effects you have. There are often things they can do to help. It can take one or two weeks after treatment before side effects start getting better. After this, most side effect usually slowly go away.

We have listed the side effects of radiotherapy to the chest below.


Radiotherapy often makes people feel tired. This can build up over your treatment. If you are having other treatments, such as surgery or chemotherapy, you may feel more tired.

We have more information on tiredness.

Skin changes

The skin in the treated area may get dry and irritated. Do not use perfumed soap or body wash during treatment, as it could irritate the skin. The hospital staff will advise you on how to look after your skin. If it becomes sore, your doctor can prescribe cream to help.

We have more information about skin changes.

Difficulty swallowing

You may have:

  • difficulty swallowing
  • heartburn
  • indigestion.

This is because radiotherapy can cause inflammation in the gullet (oesophagus).

These side effects usually happen towards the end of treatment and continue for a few weeks after it finishes. Your doctor can prescribe medicines to help reduce the symptoms.

If you have difficulty eating, you can replace meals with nutritious, high-calorie drinks. You can get these from most chemists, and your GP can prescribe some.

Breathlessness and a cough

You may find your breathing gets worse during radiotherapy and for a few weeks or months after it finishes. This is because radiotherapy can cause inflammation in the area of the lung being treated. It may also give you a dry cough. Always tell your doctor or nurse if:

  • you have these symptoms
  • these symptoms get worse.

Hair loss

This only happens in the treatment area. Men may lose hair on their chest, but it usually grows back. Occasionally hair loss is permanent.

Late effects of radiotherapy for lung cancer

Late effects are side effects that:

  • you have during treatment that do not completely get better
  • develop months or years later.

Most people do not get late effects after radiotherapy to the lung. Some possible late effects are:

  • inflammation or scarring (fibrosis) in the treated area, which can cause breathlessness or a cough
  • narrowing of the gullet (oesophagus), which makes it difficult to swallow
  • a slight increase in the risk of heart problems, which might cause pain or tightness in the chest
  • thinning of the bones in the chest area, which may cause pain in that area.

If you get any of these side effects or any others, tell your cancer doctor or nurse straight away. Also let them know if any side effects you have do not improve.