A trial of proton beam radiotherapy for oropharyngeal cancer (TORPEdO)

Please note - this trial is no longer recruiting patients. We hope to add results when they are available.

Cancer type:

Head and neck cancers
Mouth (oral) cancer




Phase 3

This trial is comparing 2 types of radiotherapy for oropharyngeal cancer. 

Oropharyngeal cancer is cancer of the part of the throat behind the mouth including cancer of the tonsils

Cancer Research UK supports this trial.

More about this trial

Doctors can treat oropharyngeal cancer with a combination of chemotherapy and radiotherapy (chemoradiotherapy Open a glossary item). The type of radiotherapy you have is intensity modulated radiotherapy (IMRT). 

Intensity modulated radiotherapy (IMRT) is a type of conformal radiotherapy. Conformal radiotherapy shapes the radiation beams to closely fit the area of cancer. 

They can form shapes that fit precisely around the treatment area. The lead leaves within the machine can move while the machine moves around the patient. This then shapes the beam of radiation to the tumour as the machine rotates.

This means that the tumour receives a very high dose and normal healthy cells nearby receive a much lower dose.

Each radiotherapy beam is divided into many small beamlets that can vary the intensity of radiation. This allows different doses of radiation to be given across the tumour.

Chemoradiotherapy works well at curing oropharyngeal cancers but the IMRT can cause short and long term side effects. These side effects can affect your quality of life.  

Proton beam radiotherapy works differently to IMRT. Protons treat cancer by producing a burst of energy when they stop. So by directing the proton beams at a cancer and making them stop inside the tumour, they destroy the cancer. And they deliver less dose to the nearby healthy cells.

So researchers think it might cause fewer side effects. 

Research and the use of proton beam radiotherapy in other countries show that it is safe and works well for cancer. 

The main aim of this trial is to find if proton beam radiotherapy causes fewer side effects than IMRT.

Who can enter

The following bullet points list the entry conditions for this trial. Talk to your doctor or the trial 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 the trial if your cancer is or isn’t caused by the human papilloma virus Open a glossary item (HPV). 

The cancer must be:

  • less than 4cm across (stage T1, T2) with cancer in the lymph node(s) of the neck Open a glossary item (N1, N2) or
  • more than 4cm across (stage T3, T4) with or without cancer in the lymph nodes of the neck (N0, N1, N2)

And all of the following apply. You:

  • have squamous cell cancer Open a glossary item oropharyngeal cancer 
  • are to have chemotherapy with radiotherapy (chemoradiotherapy) with radiotherapy to both sides of the neck 
  • are able to have at least 1 cycle of treatment  Open a glossary itemwith cisplatin 
  • are fully active but might not be able to do heavy physical work (performance status 0 or 1)
  • have satisfactory blood test results
  •  are willing to use contraception during treatment and for 2 weeks after radiotherapy if you or your partner could become pregnant
  • are at least 18 years old

Who can’t take part

You cannot join this trial if any of these apply. You:

  • have a very large lymph node that is more than 6cm in length or for HPV negative cancer the lymph node is very large and or fixed to the muscle or skin (N3) 
  • have a feeding tube because you are unable to swallow. You can join if have a feeding tube just in case it is needed. 
  • are having surgery to your neck
  • have had radiotherapy to your head or neck
  • have major surgery within 6 months of joining the trial
  • have a device in place that helps your heartbeat (pacemaker) or corrects your heartbeat (cardioverter-defibrillator) 
  • have had another cancer in the past 2 years apart from non melanoma skin cancer Open a glossary item and in situ carcinoma Open a glossary item of the cervix
  • have an active infection
  • have or had heart problems such as congestive heart failure that caused symptoms, heart attack, an abnormal heart rhythm or chest pain (angina) that happens when resting or doing very little 
  • have or had a stomach (peptic) ulcer or inflammation of the lining of the stomach (gastritis)
  • have any other medical condition or mental health problem that your doctor or the trial team think could affect you taking part
  • have problems with talking or swallowing that isn’t due to cancer that your doctor think could affect you taking part
  • are pregnant or breastfeeding

There is a sub study at The Christie Hospital in Manchester. This sub study is looking at whether a certain type of MRI scan Open a glossary item called a DWI MRI scan can help predict who might have severe side effects from treatment. 

You cannot join this sub study if any of the following apply. You:

  • can’t have an MRI scan 
  • are allergic to or have reacted to the contrast medium Open a glossary item called Gadolinium

Trial design

This is a phase 3 trial. The trial team need 201 people to join. 

Everyone has chemoradiotherapy. 

The radiotherapy part is randomised. You have either:

  • intensity modulated radiotherapy (IMRT) or
  • proton beam radiotherapy

Neither you nor your doctor can choose which group you are in.

Out of every 3 people who join, 2 people go into the proton beam group and 1 person goes into the IMRT group. 

You have radiotherapy for 6½ weeks. This is once a day Monday to Friday.

You have a planning appointment before starting treatment. This is to work out where to give the radiotherapy and how much to give. 

You have a shell (mask) made to fit over your head and shoulders. You can see through the mask. It takes about 30 minutes to make. You use the shell for your planning appointment and when you have treatment. 

Photograph of a mesh plastic mask used for radiotherapy for cancer of the head and neck and brainPlanning the radiotherapy takes about 45 minutes. 

For treatment after you lie down on the radiotherapy couch. The radiographer Open a glossary item then attaches the shell to the couch so that it covers your head and shoulders. The shell helps you lie still so that you are in the same position and have the treatment in the correct place each time you have treatment. 

People in the IMRT group have their planning and treatment at their local hospital. 

People in the proton beam group have their planning and treatment at either:

  • The Christie Hospital, Manchester or 
  • University College Hospital, London 

The proton beam key worker will arrange accommodation that is near the hospital if you don’t live in Manchester or London. You can have someone stay with you. 

Quality of life 
You fill in questionnaires:

  • before starting treatment
  • at the end of treatment
  • 6 weeks after the end of treatment
  • at 3 months then
  • every 6 months to 2 years
  • every year to 5 years

The questions ask about:

  • any symptoms
  • any side effects 
  • what you can do

This is a quality of life questionnaire

Research samples
You give blood samples a number of times during the trial. Researchers will use these to find out more about why some people have more side effects from radiotherapy than others. They will also be available for other researchers to use in the future. 

You don’t have to agree to give these samples. You can still take part in the trial. 

Sub studies at The Christies Hospital
The trial team will ask people from both groups having treatment at The Christie Hospital to take part in one or both sub studies.

The first is looking at a type of MRI scan Open a glossary item called a DWI MRI scan. As part of the sub study you might have an extra MRI scan at week 3.

The second is looking at how treatment affects cancer in the lymph nodes. This is for people who have cancer in the lymph nodes of the neck. For this sub study the team take a sample of tissue from the lymph node:

  • before starting treatment and
  • during the 3rd week of treatment 

You don’t have to agree to take part in either of these sub studies.

Hospital visits

You see the doctor to have some tests before taking part. These tests include:

  • a physical examination Open a glossary item
  • a CT scan and an MRI scan or CT scan and PET-CT scan 
  • heart trace (ECG Open a glossary item)
  • blood tests
  • hearing test
  • a jaw opening test
  • swallowing test
  • examination of the teeth (dental examination}

You see the doctor every week during treatment to see how you are and for blood tests. 

You have a planning CT scan at week 3. 

At the end of treatment you see the doctor for a physical examination and blood tests. You then see the doctor at:

  • 6 weeks
  • 3 months 
  • 6 months 
  • 1 year
  • 1 ½ years
  • 2 years then
  • every year to 5 years

Side effects

The trial team monitor you during treatment and afterwards. Contact your advice line or tell your doctor or nurse if any side effects are bad or not getting better. 

Proton beam radiotherapy might have fewer side effects than IMRT but this isn’t known for sure. And this is one of the things researchers are trying to find out. 

During your treatment side effects usually build up gradually. Most people experience some side effects. They are usually at their worst by week 5 to 6 of your treatment and continue at their peak for 2 weeks after completion of your treatment. Then over the next 4 weeks or so your treatment side effects will slowly start to get better.

Side effects of radiotherapy to this area of your body can include:

  • tiredness or fatigue
  • sore red skin to the treatment area (like a sunburn reaction) 
  • weight loss
  • a sore throat and mouth (your throat may become more sore as you go through treatment)
  • pain when swallowing
  • difficulty swallowing  
  • a dry mouth
  • loss of taste or a change in taste
  • changes to your voice

We have more information about the long term side effects of radiotherapy

Your doctor or a member of the trial team will talk to you about the possible side effects before you agree to take part.

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 David Thomson

Supported by

Cancer Research UK
Institute of Cancer Research (ICR)
The Taylor Family Foundation

Other information

This is Cancer Research UK trial number CRUK/18/010.

If you have questions about the trial please contact our cancer information nurses

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.

Last reviewed:

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