A study looking at using rectal balloons in radiotherapy for prostate cancer (BRAD)

Cancer type:

Prostate cancer

Status:

Results

Phase:

Pilot

This study was for men who were due to have radiotherapy to their prostate gland.

More about this trial

The researchers looked at a device called a rectal balloon. They were trying to find out whether it could stop the prostate gland moving and the rectum changing size or shape during radiotherapy.

Doctors often use radiotherapy to treat prostate cancer. They plan treatment very carefully using CT scans to help them.

During treatment, men might also have cone beam scans to make sure the radiotherapy is being accurately aimed at the cancer. A cone beam scan is similar to a CT scan but uses lower energy x-rays.

The area treated with radiotherapy is slightly larger than the prostate gland. One reason for this is because the prostate gland moves position slightly on a daily basis. So including a larger area ensures that the prostate is fully treated, even if it moves a little.

The size and shape of the back passage (rectum Open a glossary item ) also changes as stools and wind move through your bowel. As the rectum is very close to the prostate gland, a small part of the rectum receives some radiation when you have radiotherapy to the prostate.

Diagram showing the position of the prostate and rectum

Radiotherapy to the rectum can cause side effects such as diarrhoea and pain in the rectum.

This was a feasibility study. The study team thought it might be possible to control the size of the rectum during treatment using a device known as a rectal balloon. This would reduce the amount of radiation to the rectum. In turn, this would hopefully reduce some of the side effects men can have after radiotherapy for prostate cancer.

In this study, the researchers wanted to:

see if it was possible to use rectal balloons in a small number of men
find out if men found the procedure acceptable
know whether the balloon reduced both the movement of the prostate gland and any changes to the rectum

Summary of results

The study team found that the rectal balloon might help to keep the shape of the rectum the same during radiotherapy to the prostate gland. But the balloon did not help the rectum to be in a better position for treatment.

Ten men took part in the study. They all had external beam radiotherapy to treat their prostate cancer.

All the men had a CT scan as part of their appointment to plan their radiotherapy treatment. This is routine practice.

As part of this study, the men also had a rectal balloon placed into their back passage (rectum). The device was placed inside the back passage and the small balloon was then inflated. They then had a further CT scan with the balloon in place. The balloon was then deflated and removed.

The men had 20 treatments of radiotherapy over 4 weeks. Once a week they had a rectal balloon put in place after a radiotherapy treatment. They had a cone beam scan before the balloon was put in place and a scan with the balloon in place. The balloon was then removed.

Men had these weekly cone beam scans as part of their routine treatment. The men in this study had 2 cone beam scans each week instead of 1.

The men did not have a rectal balloon in place during their radiotherapy treatment. But researchers were able to look at the different scans and compare the appearance of the prostate gland and rectum, with and without the balloon in place.

They found that a rectal balloon:

might help to keep the rectum the same shape during radiotherapy treatment
did not help to position the rectum in a better place for radiotherapy

The study team recognised that a limit of the study was that it involved a small number of men.

Further research involving larger numbers of men is needed to look at whether this can reduce the amount of radiation to the rectum and so reduce side effects.

The men taking part were asked various questions about their experience of having the rectal balloon. For example, they were asked whether they would agree or disagree with the sentence ‘I found the placement of the balloon comfortable today’.

While some men did not find the placement of the balloon comfortable, men generally were able to tolerate having the balloon in place.

We have based this summary on information from the research team. 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 research team. We have not analysed the data ourselves.