A study looking at a PET-CT scan to plan radiotherapy for thyroid cancer (THRIFT)

Cancer type:

Thyroid cancer

Status:

Results

Phase:

Pilot

A study looking at a PET-CT scan to plan radiotherapy for thyroid cancer (THRIFT)

This study wanted to find out whether a type of scan called FLT PET-CT scan can be used to plan radiotherapy. It was for people with a type of thyroid cancer called papillary thyroid cancer.    

Papillary thyroid cancer is also called differentiated thyroid cancer.

More about this trial

Surgery and radioactive iodine are common treatments for papillary thyroid cancer. But sometimes, thyroid cancer comes back. This is called recurrent disease.

For recurrent thyroid cancer, you might have external radiotherapy. It destroys cancer cells by using radiation from a machine. Before you have external radiotherapy, you have a planning CT scan to work out how much radiation you need and exactly where you need it. 

Everyone who took part in this study had the usual planning CT scan and another scan called FLT PET-CT scan. The FLT PET-CT scan uses a radioactive substance (a tracer) called FLT to show up cancer cells. The more active a cell is, the more FLT it takes up. Cancer cells are very active, so they take up more FLT and show up more clearly on the scan. 

The main aim of this trial was to find out whether it is possible to use a FLT PET-CT scan for people with differentiated thyroid cancer.  

Summary of results

This was a small study and doctors couldn’t reach any definite conclusion about whether FLT PET-CT scans can be used to plan radiotherapy for people with differentiated thyroid cancer. 
 
This study started in 2013 and these results were reported in 2018. The study doctors recruited 2 people with recurrent papillary thyroid cancer. They both had a FLT PET-CT scan. 
 
Results
The study doctors looked at whether FLT was taken up by cancer cells. They found that FLT was taken up by cancer cells in one person (patient 2), but not the other (patient 1). 
 
Doctors know that cancer cells that are active (dividing) usually take up more FLT and show up more clearly on PET-CT scans. So, they decided to look at the number of cells who were dividing in patient 1 and patient 2. This is called the Ki-67 index. They found that: 
  • about 5 in every 100 cancer cells (5%) were dividing in patient 1
  • 20 in every 100 cancer cells (20%) were dividing in patient 2
Conclusion
The study doctors couldn’t reach any conclusion about using FLT PET-CT scans in people with thyroid cancer. But they think that this type of scan may be more beneficial for people with active (dividing) cancer cells (high Ki-67 index). 
 
Although doctors couldn’t reach any definite conclusion, they were able to learn more about thyroid cancer and the Ki-67 index. They think larger studies are needed to find out more about using FLT PET-CT scans in people with thyroid cancer.
 
We have based this summary on information from the research team.  As far as we are aware, the information they sent us has not been reviewed independently (peer reviewed Open a glossary item) or published in a medical journal yet. 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

Dr Rachel Pearson

Supported by

Experimental Cancer Medicine Centre (ECMC)
Medical Research Council (MRC)
NIHR Clinical Research Network: Cancer
The Newcastle upon Tyne Hospitals NHS Foundation Trust

Freephone 0808 800 4040

Last review date

CRUK internal database number:

11335

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

Over 60,000 cancer patients enrolled on clinical trials in the UK last year.

Last reviewed:

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