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PETReA: a trial testing whether PET scans can help make treatment decisions for people with follicular lymphoma

This phase three trial is testing whether PET scans can help determine the need for maintenance treatment in people with previously untreated follicular lymphoma.

You can share the following Identifier with your medical team so they can find out more about the trial: CRUK/16/017

Trial aim and background

The aim of this trial is to find out if PET scans can be helpful in deciding whether people with follicular lymphoma need maintenance treatment after first-line treatment. It also aims to find out:

  • if rituximab maintenance can be avoided for people with a good response to first-line treatment, preventing unnecessary side effects. 
  • if adding lenalidomide to rituximab maintenance can improve outcomes for people who have residual (leftover) lymphoma after first-line treatment.

A sub-study of the PETReA trial is looking at how effective COVID-19 vaccination is for people with follicular lymphoma.

Everyone in this trial is treated with a standard first-line treatment of chemotherapy regimen and rituximab followed by a PET and CT scan. The results of the scan is used to decide what treatment is needed next:

  1. No response to treatment - person leaves the trial and their doctor decides what treatment is needed next.
  2. Response to treatment and a negative PET scan (no active lymphoma) - person randomly assigned to one of two groups which are rituximab maintenance or no further treatment
  3. Response to treatment and a positive PET scan (still active lymphoma) - person randomly assigned to one of two groups which are rituximab maintenance or rituximab and lenalidomide maintenance

Who can enter

People over 18 with follicular lymphoma which has not previously been treated but requires treatment may be able to enter this trial.


Recruitment is taking place in the following UK locations:

  • Blackpool
  • Boston
  • Canterbury
  • Colchester
  • Derby
  • Epsom
  • Gillingham
  • Glasgow
  • Grantham
  • Leicester
  • Lincoln
  • Liverpool
  • London
  • Manchester
  • Newcastle upon Tyne
  • Nottingham
  • Oxford
  • Plymouth
  • Poole
  • Portsmouth
  • Sheffield
  • Southampton
  • Southend on Sea
  • Thornton
  • Torquay
  • Truro
  • Wales
  • Wirral

Further information

More information about what treatments are involved, the criteria you must meet in order to take part in the trial and where this trial is taking place are available at:

Lymphoma Action are not able to refer people to specific trials. If you are interested in taking part in this trial we recommend that you print the trial summary and discuss it with your medical team. They can advise you on whether you might be eligible for the trial and how you can take part based on your individual circumstances.