A study looking at improving cone beam CT scans to increase the accuracy of radiotherapy for men with prostate cancer

Cancer type:

Prostate cancer





This study looked at ways to improve the quality of a scan called a cone beam CT (CBCT) scan, to see if it could make radiotherapy for prostate cancer more accurate.

If you have radiotherapy to treat prostate cancer you will have a CT scan to help doctors plan exactly where to aim the radiotherapy beam. But your prostate gland can move slightly in the body, so doctors treat a small area around the prostate as well (a safety margin). If this includes part of the back passage (rectum), it can cause diarrhoea and other possible bowel problems in the future.

If they can see the prostate and rectum more clearly during radiotherapy, they might be able to use a smaller safety margin. This could reduce side effects of treatment.

In this study they used a scan called a cone beam CT (CBCT), which takes pictures in 3D. When this study was done, the quality of CBCT scans wasn’t always good enough to identify the prostate as accurately as needed.

The aim of the study was to see if different methods of CBCT could improve the quality of the image used during prostate cancer radiotherapy.

Summary of results

The research team found that doctors should be cautious about reducing the radiotherapy area based on CBCT scans.

This trial recruited 31 people who were due to have radiotherapy for prostate cancer. They all had cone beam CT (CBCT) scans. The researchers used 3 different types of CBCT scans.

The research team trained 2 doctors and 6 radiographers to read the scans. They looked at each 3D scan in 3 ways – left to right, front to back, and top to bottom.

The researchers looked at the results once the scans had been read. They found that some of the readings were good and consistent. But there was some variation between readers.

They concluded that cone beam CT scans could help provide extra information to help make sure the prostate is targeted accurately. But care should be taken when reducing the safety margin because of the variation between different people who read the scans.

We have based this summary on information from the team who ran the study. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item) but may not have been published in a medical journal.  The figures we quote above were provided by the trial team. We have not analysed the data ourselves.

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 D Dearnaley

Supported by

Cancer Research UK
Institute of Cancer Research (ICR)
NIHR Clinical Research Network: Cancer
The Royal Marsden NHS Foundation Trust

If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle 9158

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

Last reviewed:

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