Around 1 in 5 people diagnosed with cancer in the UK take part in a clinical trial.
A trial looking at a second treatment of radiotherapy for cancer that has spread to the bone (SC20 trial)
This trial looked at the possibility of using a second radiotherapy session for pain caused by cancer that had spread to the bone. This trial was supported by Cancer Research UK.
Cancer can spread to the bone and it can be painful. Doctors can treat painful cancer spread to the bones with radiotherapy, which often works very well.
But sometimes it doesn’t work. Or it only works for a short time and then the pain comes back again. If this happens, some doctors give a second radiotherapy session, and some don’t. No one was sure how well a second radiotherapy session worked. Or what was the best dose to give.
In this trial, people who had already had radiotherapy to their bones once, but were still having pain, had more radiotherapy. They either had a low dose of radiotherapy in a single session (
The aims of the trial were to find out how well a second radiotherapy session worked for pain caused by cancer spread to the bones. And which dose of radiotherapy was best.
Summary of results
The trial team found that a lower dose in a single session of radiotherapy was as good as a higher dose in 5 sessions as a second treatment for bone pain caused by cancer.
- Half of the people in the trial had a single session of radiotherapy
- Half of the people in the trial had 5 sessions of radiotherapy
The researchers looked at how people were 2 months after their treatment. They found that the bone pain had responded in
- 28 out of every 100 people (28%) who had the single radiotherapy session
- 32 out of every 100 people (32%) who had the 5 radiotherapy sessions
The trial team then did a 2nd analysis. They took out those people who
- Didn’t have radiotherapy as instructed in the protocol of the trial
- Unfortunately died before the team could follow them up to assess their bone pain
This left them with the number of people in each group who were treated and followed up according to the protocol of the trial. There were
- 285 people who had a single radiotherapy session
- 263 people who had 5 radiotherapy sessions
Out of these people, the researchers found that bone pain had responded in
- 45 out of every 100 people (45%) who had the single radiotherapy session
- 51 out of every 100 people (51%) had 5 radiotherapy sessions
This could have happened by chance, so it wasn't
Two weeks after radiotherapy the most common side effects reported were loss of appetite and diarrhoea.
The trial team concluded that a low dose of radiotherapy in a single session was no worse than a higher dose in 5 sessions as a second treatment for bone pain caused by cancer.
We have based this summary on information from the team who ran the trial. The information they sent us has been reviewed by independent specialists (
How to join a clinical trial
Professor Peter Hoskin
Cancer Research UK
National Institute for Health Research Cancer Research Network (NCRN)
This is Cancer Research UK trial number CRUK/04/002.