A study looking at changes to DNA in people having radiotherapy

Please note - this trial is no longer recruiting patients. We hope to add results when they are available.

Cancer type:

All cancer types





This study is looking at the level of damage and repair to DNA in white blood cells after treatment with radiotherapy. Radiotherapy uses X-rays to destroy cancer cells. It works by causing damage to the genetic code (DNA) which tells cells how to behave.

As well as damaging cancer cells, radiotherapy can also affect healthy cells near to where the treatment is being aimed. This can cause different side effects, depending on where to the body you have treatment.

Researchers in this study want to understand more about the radiation dose that affects healthy cells. They want to measure this dose by looking at very low levels of DNA damage in white blood cells. Researchers hope that this study will give them more information about the way radiotherapy affects cells after treatment.

The aim of this study is to look at the level of DNA damage and repair in white blood cells after radiotherapy, and to see how this may be linked to radiotherapy treatment. You will not have any direct benefit from taking part in this study, and it is unlikely to change your treatment plan in any way. But the results of the study will be used to help people with cancer in the future.

Who can enter

You can enter this study if you have cancer and you

  • Are due to start a course of radiotherapy
  • Would be able to come to hospital for the follow up appointments

You cannot enter this study if you

  • Are having chemotherapy either before, or at the same time as, your course of radiotherapy (chemoradiation Open a glossary item)
  • Have any condition apart from your cancer that would make you unwell, or affect the results of the study – you can check this with your doctor

Trial design

This study will recruit 20 people each year. Everyone will have a series of blood tests.

You will give a blood sample before and after your radiotherapy session, everyday for the first week, and then every week for the rest of your treatment. And then on 2 separate visits after this.

The study staff will take blood from a vein in your arm before and after your radiotherapy session. They may put a thin plastic tube in a vein in the arm that is left in for the whole of the session. Having this needle means that you only have to be pricked once instead of twice each time. They will remove the tube after the second blood sample each time, before you go home.

The study team will also record information about your radiotherapy dose, and look for DNA damage in your white blood cells.

Hospital visits

On your blood test days, you will need to stay in the department for an hour after your radiotherapy treatment, so that you can give the second sample.

You also come back for extra visits to the department for a blood test 2 weeks and 6 weeks after you finish your course of radiotherapy.

Side effects

Your radiotherapy is part of your planned treatment, and is not part of the study. Tiredness is a common side effect of radiotherapy, and the team think the extra time you will spend at the hospital to give these blood samples may make you feel more tired.

You may have a small bruise where you gave your blood sample.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Professor Susan Short

Supported by

Experimental Cancer Medicine Centre (ECMC)
NIHR University College London Hospitals Biomedical Research Centre
University College London Hospitals NHS Foundation Trust

Questions about cancer? Contact our information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Cara took part in a clinical trial

A picture of Cara

"I am glad that taking part in a trial might help others on their own cancer journey.”

Last reviewed:

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