A study to find out whether PET scans can measure the amount of the HER2 protein in breast cancer (HERPET)

Cancer type:

Breast cancer




This trial is for women who have had a biopsy to check for the levels of human epidermal growth factor (HER2) receptors Open a glossary item in the last year.
It is for people who have either:
  • large amounts of the HER2 receptors (HER2 positive)
  • small amounts of the HER2 receptors (HER2 negative) 

More about this trial

Everyone diagnosed with breast cancer has a test to find out the amount of HER2 proteins in their cancer. This is because you have different treatments depending on whether your cancer is HER2 positive or HER2 negative. 
The current way to check for the levels of HER2 is by taking a sample of breast cancer tissue when you are first diagnosed (biopsy). But biopsies can have some risks such as bleeding and pain. 
In this study, doctors want to find out whether PET scans can tell who has HER2 positive and HER2 negative breast cancer. 
A PET scan uses a mildly radioactive drug (a tracer) to show up areas of your body where cells are more active than others. It is a common test to diagnose cancer. 
Everyone taking part in this study has a PET scan with a new tracer called [18F]GE-226. 
The main aim of this trial is to find out whether PET scans can be used to measure the amount of HER2 protein in breast cancer. 
Please note – you will not get direct benefit from taking part in this study. 

Who can enter

The following bullet points list the entry conditions for this study. Talk to your doctor or the study team if you are unsure about any of these. They will be able to advise you. 
Who can take part
You may be able to join this study if you are a woman and all of the following apply. You:
  • have HER2 positive or HER2 negative breast cancer  
  • have at least 1 area of cancer that measures more than 1.5cm across and you haven’t had radiotherapy to that area
  • have had a biopsy to measure the amount of the HER2 protein in the last year
  • have had scans to find out the stage Open a glossary item of your cancer in the last 6 weeks
  • are up and about more than half the day, can look after yourself but can’t work (performance status of 0, 1 or 2)
  • have satisfactory blood tests results  
  • are at least 18 years old 
Who can’t take part
You cannot join this study if any of these apply. You:
  • have heart problems such as an abnormal heart rhythm, problems with the valves and the muscle of your heart, or you have had a heart attack
  • are taking, or have taken an experimental drug in the last 2 weeks  
  • can’t have a PET scan for any reason, for example you have a fear of being in confined spaces (claustrophobia) or you can’t lie flat
  • take a large amount of drugs to help prevent blood clots Open a glossary item such as warfarin 
  • have any other medical condition that the trial team think could affect you taking part 
  • work on or near radiation (radiation worker)
  • are pregnant or breastfeeding 

Trial design

Researchers hope that up to 8 people with HER2 positive and 8 people with HER2 negative breast cancer will agree to take part. 
Everyone has a PET scan with the new [18F]GE-226 tracer. 
Before you have the scan, you have 2 small plastic tubes (cannulas) put into your arm. You have one tube put into a vein and the second tube put into an artery. 
To have the scan, you lie down on the machine couch on your back. The couch slowly moves through the scanner as the machine takes the pictures. 
You have a CT scan first, which takes about a minute. You then have the PET scan. Your radiographer uses one of the tubes to give you the tracer. And the other tube to take blood samples during the scan. 
About 60 minutes after the start of the scan, your radiographer might ask you to pass urine. After you passed urine, you return to the PET scanner to have the final part of the scan. It takes about 90 minutes in total to have the PET scan. 
Blood samples
As part of this study, doctors need some extra blood samples for research. They want to:
  • look for certain proteins (biomarkers Open a glossary item) that can help to tell why some treatments work better than others
  • check the levels of [18F]GE-226 tracer in your body
You have the extra blood tests 30 minutes before and at set times during the PET scan. 
Tissue sample
The study team will ask to use a tissue sample of your cancer taken when you had surgery or a biopsy. They may ask you to have a new tissue sample taken if there isn’t a suitable sample available. 
You don’t have to agree to have a new tissue sample taken if you don’t want to. You can still take part in this study.  

Hospital visits

You see the study doctor and have some tests before and 30 minutes after your PET scan. These tests might include:
  • a physical examination
  • blood tests
  • heart trace (ECG Open a glossary item
  • an ECHO Open a glossary item
  • urine tests
You go home after you have had the scan and have seen the doctor. You then see the study doctor again 24 hours after your scan. They check how you are and whether you have taken any new drugs. You might also have:
  • a physical examination
  • blood tests
  • urine test

Side effects

Your radiographer monitors you during the scan and you see the doctor before you go home. When you go home, you have a phone number to call if you are worried about anything. The team will tell you about all the possible side effects before you have the scan. 

PET scans are safe tests and most people don’t have any side effects from it. This is the first time that people will have a PET scan with the [18F]GE-226 tracer so there might be side effects we don’t know about it yet.

You may have some bruising and bleeding around the areas where they put the tubes (cannulas) in. You are also exposed to some radiation from the tracer during the scan. This can slightly increase your risk of developing cancer in the future. This has been reviewed and approved by the Administration of Radioactive Substances Advisory Committee (ARSAC). Talk to the study team if this worries you. 

We have more information about the possible risks of PET scans. 



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 Laura Kenny

Supported by

Medical Research Council
Imperial College London
Imperial College Healthcare NHS Trust.

Freephone 0808 800 4040

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.

Harriet wanted to try new treatments

A picture of Harriet

“I was keen to go on a clinical trial. I wanted to try new cancer treatments and hopefully help future generations.”

Last reviewed:

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