A trial to find the best way to give radiotherapy for people with small cell lung cancer (CONVERT)

Cancer type:

Lung cancer
Small cell lung cancer




Phase 3

This trial looked at whether it is best to have radiotherapy twice or once a day. It was for people whose small cell lung cancer hadn’t spread elsewhere in the body and who were having cisplatin and etoposide chemotherapy.

Cancer Research UK supported this trial.

More about this trial

Chemotherapy and radiotherapy are usual treatments for small cell lung cancer. We know from research that having both treatments can control the cancer for longer.

There are different ways of having this treatment. Some people have radiotherapy and chemotherapy at the same time (chemoradiotherapy). Others have one treatment after the other. Some people have radiotherapy twice a day, others once a day.

Researchers wanted to find the best way to combine radiotherapy with chemotherapy and if people having once daily radiotherapy would live longer compared to people having twice daily radiotherapy.

In this trial, they looked for the best dose of radiation to give, and how many days to split the treatment into.

The aims of this trial were to find:

  • the best total dose of radiotherapy to give
  • whether radiotherapy works best when you have it twice or once a day

Summary of results

The trial team found that having radiotherapy once a day worked as well as having it twice a day when you have it alongside chemotherapy.

547 people took part in the trial. They were put into 1 of 2 groups at random.

  • 274 had radiotherapy twice a day for 3 weeks
  • 273 had radiotherapy once a day 6 ½ weeks

Everyone in the trial had cisplatin and etoposide chemotherapy. These are standard chemotherapy drugs for small cell lung cancer. They had up to 6 cycles of treatment. They began radiotherapy 3 weeks after the first cycle of chemotherapy.

People having radiotherapy twice a day, had a gap of around 6 to 8 hours between treatments each day.

The trial team looked at the number of people living 2 years after treatment. They found this was:

  • just under 6 out of 10 people (56%) in the group having radiotherapy twice a day
  • just over 5 out of 10 people (51%) in the group having radiotherapy once a day

People who had radiotherapy twice a day had more problems with a drop in white blood cells (neutropenia). Apart from that, the side effects were similar in both groups.  

The main finding of the trial is that once daily radiotherapy does not improve the number of people living 2 years after treatment. Either once daily or twice daily radiotherapy alongside chemotherapy can be given as standard treatment for small cell lung cancer that hasn’t spread. This means patients and doctors can choose together which treatment suits them best.

Other findings included:

  • finding the best dose of radiotherapy to give to this group of people – before there was no agreed dose for giving radiotherapy once or twice a day
  • that people with small cell lung cancer live longer and have fewer side effects than previous studies reported - this is likely to be because of the use of modern radiotherapy techniques

The trial team concluded that once daily radiotherapy alongside chemotherapy does not improve the survival of people with small cell lung cancer that hasn’t spread elsewhere in the body. Both twice and once daily treatments can be considered for treatment in the clinic.

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.

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 Corinne Faivre-Finn

Supported by

Cancer Research UK
The Christie NHS Foundation Trust
The Manchester Academic Health Science Centre Clinical Trials Unit
Experimental Cancer Medicine Centre (ECMC)
European Organisation for Research and Treatment of Cancer (EORTC)
NIHR Clinical Research Network: Cancer
National Institute of Canada Clinical Trials Group (NCIC CTG)
Spanish Lung Cancer Group (GECP)
French Lung Cancer Group (GFPC)

Other information

This is Cancer Research UK trial number CRUK/07/005.

We have more information about the work of Professor Corinne Faivre-Finn.

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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.

Around 1 in 5 people take part in clinical trials

3 phases of trials

Around 1 in 5 people diagnosed with cancer in the UK take part in a clinical trial.

Last reviewed:

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