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Radiotherapy for acute lymphoblastic leukaemia (ALL)

Radiotherapy uses high energy x-rays, to treat cancer cells. You might have radiotherapy as part of your treatment for acute lymphoblastic leukaemia (ALL).

ALL treatment uses external radiotherapy. External radiotherapy uses a radiotherapy machine to aim radiation beams at the cancer. The most common type of external radiotherapy for ALL is total body irradiation or TBI. You have this as part of a donor transplant Open a glossary item.

You might also have radiotherapy to the brain or spinal cord if leukaemia cells have spread there.

Planning your treatment

Before you start radiotherapy treatment, your radiotherapy team has to carefully plan it. This means working out how much radiation you need and exactly where you need it. You usually have a CT scan to help plan your treatment.

As part of your radiotherapy planning for brain or spinal cord radiotherapy, you’ll have a mask or mould made. This keeps your head very still and in the correct position while you have treatment.

After radiotherapy planning

You might have to wait a few days or up to 3 weeks before you start treatment. During this time the physicists and your radiotherapy doctor (clinical oncologist) decide the final details of your plan.

Then the physicists and staff called dosimetrists plan the treatment very precisely using computers.

Total body irradiation (TBI)

You usually have TBI alongside high dose chemotherapy drugs. This is part of your preparation for a stem cell or bone marrow transplant.

TBI alongside chemotherapy helps to kill off leukaemia cells in the bone marrow. It also helps to suppress the immune system to prevent rejection of the donor stem cells.

You usually have TBI treatment twice a day for 3 or 4 days. Or it may be just 1 or 2 radiotherapy treatments. It all depends on your treatment plan.

Your doctors and therapy radiographers Open a glossary item will go through your treatment plan with you. 

Radiotherapy to the brain or spinal cord

You might have radiotherapy to treat leukaemia cells that have spread to the brain or spinal cord. The number of treatments you need will depend on your individual situation and treatment plan.

The radiotherapy room

Radiotherapy machines are very big and could make you feel nervous when you see them for the first time. The machine might be fixed in one position or able to rotate around your body to give treatment from different directions. The machine doesn't touch you at any point.

Before your first treatment, your therapy radiographers Open a glossary item will explain what you will see and hear. In some departments the treatment rooms have docks for you to plug in music players. So you can listen to your own music while you have treatment.

Photo of a linear accelerator

Treatment sessions

Your radiographers help you get into position on the treatment couch. This is the same position as in your planning appointment. This can take up to half an hour.

If you need to wear a mask for your radiotherapy, they will position the mask over your face and attach it to the table. The mask keeps your head completely still while you have treatment.

If you are having TBI, you have small radiation monitors taped to some areas of your body. This is to check on the amount (dose) of radiation you’re getting.

The lights in the room dim for a few minutes while the radiographers position you. They leave the room while the machine is on. They can watch you on closed circuit TV during the treatment. It is important that you stay as still as you can, but you can breathe normally.

You have a buzzer that you can press at any time if you need the treatment to stop. You don't feel anything but when the machine is on, you will hear a beeping noise.

We have more information about having TBI treatment in our general treatment section. Remember to click back to return to the ALL section.

We also have information about having external radiotherapy.

You won't be radioactive

This type of radiotherapy won't make you radioactive. It's safe to be around other people, including pregnant women and children.

Side effects of radiotherapy

Radiotherapy affects people in different ways, so it's difficult to predict exactly what side effects you’ll have and how bad they might be. Some people only have mild side effects but for others, the side effects can be more severe. The side effects of radiotherapy depend on which part of the body you're having treatment too.

Your radiotherapy team will talk to you about the possible side effects before you start treatment. They will help you manage any side effects you have.

Most side effects will improve a few weeks after treatment. But some can continue for months or years afterwards (long term side effects). Some side effects might be permanent.


Common early side effects include:

  • feeling or being sick
  • hair loss
  • tiredness
  • loose poo (diarrhoea)
  • increased risk of infection
  • mouth sores or ulcers
  • skin changes such as reddening of your skin, darkening and feeling dryness

Possible long term side effects might include:

  • clouding of the lens inside your eye (cataracts)
  • shortness of breath and cough due to inflammation of the lung tissue
  • being unable to have children naturally (infertility)
  • developing a second cancer, but this is rare

Brain and spinal cord

Some of the common early side effects include:

  • feeling or being sick
  • hair loss
  • tiredness
  • loose poo (diarrhoea)
  • skin changes such as reddening of your skin, darkening and feeling dryness
  • headaches
  • hearing problems

Some of the long term side effects include:

  • clouding of the lens inside your eye (cataracts)
  • developing a second cancer
  • sensitive skin on your head from exposure to the sun
Last reviewed: 
29 Jul 2021
Next review due: 
29 Jul 2024
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    D Hoezler and others
    Annals of Oncology, 2016. Volume 27, Supplement 5, Pages V69 to V82

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    C Pinnix and others
    International Journal of Radiation Oncology, 2018. Volume 102, Issue 1, Pages 53-58

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    M Kenyon and A Babic
    Springer Open, 2018

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    Wolters Kluwer, 2019

  • Hoffbrand’s Essential Haematology (8th Edition)
    AV Hoffbrand and D A Steensma
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  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact with details of the particular issue you are interested in if you need additional references for this information.