A study looking at DNA and tissue damage in men having radiotherapy for prostate cancer

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

Cancer type:

Prostate cancer





This study is looking at blood samples from men having radiotherapy to cure prostate cancer. Radiation kills cells by damaging the DNA inside them. Having radiotherapy kills cancer cells, but also damages nearby healthy cells close to the area being treated.

More about this trial

The body begins to repair this damage straight away, but doctors don’t fully understand this repair process. In this study they will look for signs of cell damage and repair in blood samples from men having different types of radiotherapy for prostate cancer.

Healthy cells in the bowel and bladder can be damaged during radiotherapy for prostate cancer. So the study team will ask you to fill out questionnaires about any side effects you may have. A chemical in the blood called citrulline is related to bowel health. By measuring this and comparing with your answers, the team hope to better understand how radiation affects the bowel.

The researchers will also look for prostate cancer cells that may have broken away from the cancer and may have leaked into the bloodstream.

Doctors hope that this research will tell them more about how radiation damages DNA during treatment and give them better ways of predicting side effects. This might help them to improve treatment. You will not have any direct benefit from taking part in this study, and it will not change your treatment plan in any way. But the results of the study will help men with prostate cancer in the future.

Who can enter

You may be able to enter this study if you

  • Have the most common type of prostate cancer called adenoma of the prostate
  • Are well enough to be up and about for at least half the day (performance status 0, 1 or 2)
  • Are going to have a type of radiotherapy called either 3DCRT, IMRT Open a glossary item or brachytherapy, and this is aimed to cure your cancer rather than to control symptoms
  • Are at least 18 years of age

You cannot enter this study if

  • You are having chemotherapy or any trial medication
  • You have had radiotherapy before
  • You have any long term bowel condition or damage
  • You have a condition where your immune system Open a glossary item attacks your body in some way, such as rheumatoid arthritis
  • You have an uncontrolled infection
  • You have diabetes Open a glossary item, or another condition that means you can’t fast overnight
  • Your kidneys do not work properly
  • You have any other condition that is uncontrolled and may make you unwell if you took part, or affect the results of the study – you can check this with your doctor

If you are suitable to take part but are already on a clinical trial Open a glossary item, the study team will ask your trial doctor for permission for you to join this too, as long as the trial you are on won’t affect or be affected by what doctors are looking at here.

Trial design

This study will recruit 50 men. Everyone taking part will give a series of blood samples over about 9 months. The number of samples you give depends on the type of radiotherapy you are having.

If you are having radiotherapy from outside your body (external beam radiotherapy) you give 12 blood samples. You give samples before, during and after your course of radiotherapy. Most of these will be when you come for your radiotherapy.

If you are having internal radiotherapy (called brachytherapy), you give a total of 8 blood samples.

You will need to spend some extra time at the hospital for some of these blood tests, and for some you will need to have nothing to eat or drink (you will fast) overnight before the tests. The team will tell you more about the timings and fasting.

Everyone will regularly fill out a questionnaire, asking about side effects and how you have been feeling. This is called a quality of life study. You do this 6 times in the first year. And then, once a year for the next 5 years.

Hospital visits

You will usually give your study blood samples and fill out your questionnaires when you are at a routine appointment.

You will need to wait 4 hours after either your planning CT scan (external radiotherapy patients) or the start of your brachytherapy to give blood samples.

If you are having external radiotherapy, you will also need to wait for an extra hour after your treatment to give a blood sample twice a week.

Everyone will make 2 extra hospital visits for the study

  • For an extra clinic visit
  • To give a blood sample the day after either your routine CT scan (if you are having external radiotherapy) or starting brachytherapy

Side effects

You may have a small bruise where you give blood samples.

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 Joe O'Sullivan

Supported by

Belfast Health & Social Care Trust
Experimental Cancer Medicine Centre (ECMC)
Friends of the Cancer Centre
Queen's University

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.

Keith took part in a trial looking into hormone therapy

A picture of Keith

"Health wise I am feeling great. I am a big supporter of trials - it allows new treatments and drugs to be brought in.”

Last reviewed:

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