A trial looking at different ways of giving radiotherapy for bladder cancer (RAIDER)
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This trial looked at different doses of radiotherapy for 
. It was for people whose cancer had grown into the wall of the bladder. This is called muscle invasive bladder cancer.
The trial was supported by Cancer Research UK. It was open for people to join between 2015 and 2020. The team published the results in 2024.
More about this trial
Doctors often use radiotherapy to treat muscle invasive bladder cancer. First they have to plan exactly where to give the radiotherapy. A CT scan helps show the position and shape of the bladder.
The bladder can move a bit from day to day, depending on how full it is. So doctors include an area of tissue around the cancer in the treatment plan. This helps make sure they don’t miss any of the cancer if the bladder moves a bit. But treating healthy tissue can cause side effects.
This trial looked at something called adaptive tumour focussed radiotherapy. The doctors use the CT scan results to plan 3 possible treatment areas of different sizes – small, medium and large. The person having treatment has a scan before each dose of radiotherapy. The doctor then chooses the best treatment plan for that day.
This means they give a higher dose of radiotherapy to the area of cancer. And a lower dose to the rest of the bladder and the healthy tissue around it. They hope this will mean people have fewer side effects.
There were 3 treatment groups in this trial. People taking part had either:
- standard dose radiotherapy - also called whole bladder radiotherapy (WBRT)
- standard dose adaptive tumour focussed radiotherapy (SART)
- higher dose adaptive tumour boost radiotherapy - also called dose escalated adaptive tumour boost radiotherapy (DART)
Radiotherapy is split into individual doses called fractions. In each of the 3 main treatment groups, some people had 20 fractions and some had 32 fractions.
The people who had 32 fractions had a lower dose in each fraction. But a higher dose overall.
The people who had DART had a higher dose of radiotherapy in each fraction and in total.
The main aims of this trial were to find out:
- if it’s possible for radiotherapy departments to use adaptive tumour focussed radiotherapy
- more about the side effects
- how well the different treatment plans work
Summary of results
This trial showed that it was possible to use adaptive tumour focussed radiotherapy. And that it didn’t cause too many side effects.
Results
A total of 345 people joined this phase 2 trial in total. They were put into a treatment group at random. There were:
- 87 people in the standard whole bladder radiotherapy (WBRT) group
- 87 people in the standard dose adaptive tumour focused radiotherapy (SART) group
- 171 people in the dose escalated adaptive tumour boost radiotherapy (DART) group
Radiotherapy is given in individual doses called fractions. In each of these treatment groups:
- about half the people had 20 fractions
- about half the people had 32 fractions
Side effects
The trial team looked at how many people in each group had long term side effects. This means side effects between 6 and 18 months after they finished radiotherapy.
Some people taking part did have side effects such as bladder irritation or issues passing urine. But these were often mild or didn’t last long.
Three people in the 20 fraction groups had a more severe side effect:
- 1 person in the 20 fraction WBRT group had inflammation of the bladder (cystitis)
- 1 person in the 20 fraction SART group had a blockage (obstruction) in the urinary tract
- 1 person in the 20 fraction DART groups had a serious infection that started in the bladder (urosepsis)
No one in the 32 fraction groups had a more severe side effect.
How well treatment worked
The trial team looked at how many people’s cancer had not come back, 2 years after joining the trial. They found it was it was similar in the different groups:
- fewer than 7 out of every 10 people (66%) in the WBRT or SART group
- more than 7 out of every 10 people (74%) in the DART group
They also looked at how many people were living, 2 years after starting treatment. They found this was also similar in the different groups:
- just under 8 out of every 10 people (77%) who’d had WBRT or SART
- 8 out of every 10 people (80%) who’d had DART
The trial team assessed people’s during and after treatment. They found there was little difference between the groups.
Which treatment plan people had
The trial team looked at how many times they used the small, medium and large treatment areas.
They used the medium treatment plan for about 4 out of 10 fractions (42%). This is the standard treatment area. So they used an adapted area for just under 6 out of 10 fractions.
They used the:
- small area for just under 4 out of 10 fractions (37%)
- large area for just over 2 out of 10 fractions (21%)
Conclusion
The trial team concluded that it was possible for radiotherapy departments to give adaptive tumour focused radiotherapy for muscle invasive bladder cancer. And that dose escalated adaptive tumour boost radiotherapy (DART) didn’t cause many long term side effects.
They suggest this is looked at more in other trials.
More detailed information
There is more information about this research in the reference below.
Please note, the information we link to here is not in plain English. It has been written for healthcare professionals and researchers.
Dose-escalated Adaptive Radiotherapy for Bladder Cancer: Results of the Phase 2 RAIDER Randomised Controlled Trial
R Huddart and others
European Urology. Published online 7th October 2024.
Where this information comes from
We have based this summary on the information in the article above. This has been reviewed by independent specialists () and published in a medical journal. We have not analysed the data ourselves. As far as we are aware, the link we list above is active and the article is free and available to view.
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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.
Chief Investigator
Professor Robert Huddart
Supported by
Cancer Australia
Cancer Research UK
Cancer Society of New Zealand
Clinical Trials and Statistics Unit at the Institute of Cancer Research (ICR-CTSU)
The Institute of Cancer Research (ICR)
NIHR Clinical Research Network: Cancer
The UK National Radiotherapy Trials Quality Assurance (RTTQA) Group
NIHR Biomedical Research Centre
Other information
This is Cancer Research UK trial number CRUK/14/016.
If you have questions about the trial please contact our cancer information nurses
Freephone 0808 800 4040
