Radiation therapy for lung cancer

Also known as radiotherapy, radiation therapy is the use of a controlled dose of radiation to kill or damage cancer cells so they cannot grow, multiply or spread.

Learn more about:

• Overview
• Standard external beam radiation therapy (EBRT)
• Stereotactic body radiation therapy (SBRT)
• Planning radiation therapy
• Having radiation therapy
• Side effects of radiation therapy
• Video: What is radiation therapy?

Overview

Radiation therapy may be given on its own, after surgery or with chemotherapy (called chemoradiation). It may be recommended:

• if you are unable or choose not to have surgery
• to treat locally advanced (stage 3) NSCLC or limited-stage SCLC
• after surgery, if there is some cancer left behind (called a positive margin)
• after surgery, if tests show cancer in the lymph nodes between the lungs, to reduce the risk of cancer coming back in this area
• as palliative treatment to improve quality of life by relieving pain or other symptoms.

For lung cancer, the radiation is usually in the form of x-ray beams that come from a machine outside the body. This is called external beam radiation therapy (EBRT). It can be delivered in different ways depending on the type and stage of lung cancer.

Standard external beam radiation therapy (EBRT)

This is usually given Monday to Friday over several weeks. For NSCLC, treatment aimed at making the signs and symptoms of cancer go away (curative course) may involve 20–30 radiation therapy sessions over 4–6 weeks. Palliative radiation therapy may involve up to about 10 treatments. For SCLC, treatment may be given twice a day for 3 weeks (about 30 treatments).

Stereotactic body radiation therapy (SBRT)

This is also called stereotactic ablative body radiation (SABR). It is a way of giving a very precise high dose of radiation therapy to small, early-stage NSCLC.

SBRT may be used when you are not well enough to have surgery, or surgery is not possible due to the location or size of the cancer. SBRT is often given as 3–4 treatment sessions over a couple of weeks. It is suitable only for tumours that are not close to major airways or major blood vessels.

How SBRT is done

Stereotactic body radiation therapy (SBRT) precisely target beams of high-dose radiation from different angles onto the tumour.

Planning radiation therapy

Before treatment starts, you will have a planning session at the radiation therapy centre to design a treatment plan for you. During this appointment, you will have a CT scan to pinpoint the area to be treated, and marks will be put on your skin so the radiation therapist treats the same area each time. Often, you will have a 4-dimensional CT scan to monitor how the lung cancer moves as you breathe in and out. You may also be given some breathing exercises to help your breathing stay as regular as possible during the treatment sessions.

Having radiation therapy

Radiation therapy is delivered using a large machine called a linear accelerator. Each treatment day, a radiation therapist will help you to lie on the treatment table and make sure you are in the correct position before leaving the room. Before the radiation therapy is given, you will have an x-ray or CT scan to make sure the correct area is being treated. The radiation treatment itself takes only a few minutes, but a session may last 10–20 minutes because of the time it takes to set up the machine.

Linear accelerator

Side effects of radiation therapy

Radiation therapy itself is painless, but the radiation may affect some tissues of the body and cause various side effects. These side effects vary depending on the dose of radiation, the number of treatments and the part of the chest treated. Most are temporary and disappear a few weeks or months after treatment.

Discomfort when swallowing and heartburn 

If the cancer is in the centre of the chest and near the oesophagus, you may have some discomfort when swallowing, and heartburn during the treatment period and up to 4 weeks after treatment ends. Until these side effects improve, you may need to eat soft foods and avoid hot drinks.

Fatigue 

Feeling tired is common after radiation therapy. Plan your daily activities so you can rest regularly. You may find that gentle physical exercise helps to reduce fatigue.

Skin changes 

The skin on your chest and back may become red or dry, like sunburn. It is important to avoid getting direct sunlight on these areas. Applying a moisturising cream daily can help protect your skin – talk to your medical team about which products they recommend.

Shortness of breath and cough 

Radiation therapy may cause inflammation of the lungs. Called radiation pneumonitis, this may cause shortness of breath and/or a cough. This may happen during treatment, but it is more likely to appear 1–6 months after treatment ends. Radiation pneumonitis is usually temporary and can be treated.

Side effects can change from one treatment session to the next and may build up over time. Tell the radiation oncology team about any side effects you have, as most can be managed.

For more on this, see Radiation therapy.

→ READ MORE: Chemotherapy for lung cancer

Video: What is radiation therapy?

Watch this short video to learn more about radiation therapy.