Publish date: 16 September 2024

More than 400 patients at UCLH have so far benefited from an exciting new cancer treatment called proton beam therapy (PBT) – which uses high-energy beams of protons, rather than X-rays, to deliver a dose of radiotherapy.

PBT is highly targeted and so reduces the risk of radiation damage to healthy tissues surrounding the tumour. Depending on the patient, PBT may be used alone, or in combination with other radiation therapy, surgery, and/or chemotherapy.

As one of only two NHS proton beam centres in the UK, our new centre at UCLH brings together some of the world’s leading specialists in complex cancers.

We are also driving forward research in PBT – to find out which patients it works best for, how best to deliver it, and how to measure its impact.

In this article, we look at PBT trials currently underway at UCLH, supported by our National Institute for Health and Care Research Biomedical Research Centre at UCLH.

Research such as these clinical trials and projects are supported by very many people behind the scenes and are coordinated by a specific Proton Beam research delivery team within UCLH Cancer Clinical Trials Unit. They are also supported by the NIHR Research Delivery Network.

For more information on all our clinical trials at UCLH, please consult our trials database.


UCLH consultant Dr Crispin Hiley is leading the first ever randomised control trial of PBT for mesothelioma, a cancer which begins in the tissues lining the lungs.

There are limited treatments for mesothelioma and low survival rates. Conventional radiotherapy is effective for some lung cancers, but is not normally used in mesothelioma because the amount of lung tissue needing treatment with radiation is large, potentially leading to a high rate of side effects.

Researchers in the HIT-MESO trial hope that PBT for mesothelioma will greatly reduce radiation to the heart, other lung and other nearby organs, improving treatment success.

The APPROACH study, led at UCLH by neuro-oncology clinical oncologist Dr Michael Kosmin, will look at PBT in oligodendroglioma (ODG), a rare type of brain tumour.

Radiotherapy, normally delivered using photon radiation, is an important part of treatment. ODG and has a good prognosis overall, with median survival in excess of 10 years. However, photon radiation can damage the healthy brain surrounding the tumour resulting in long-term irreversible side effects including cognitive decline.

The study team hope to show that use of PBT will spare more surrounding healthy brain tissue, and reduce future cognitive decline.

A trial led by UCLH Head of Radiation Oncology Prof Maria Hawkins aims to reduce side effects linked with treatment for oesophageal cancer.

The current standard of care is chemotherapy and radiotherapy. These improve overall survival, but often lead to post-operative lung and cardiac complications.

In the PROTIEUS trial, the team will see if giving PBT can reduce these side effectives by sparing normal tissues compared with standard radiotherapy.

UCLH is part of the first UK trial to test the benefits of proton beam therapy for certain patients with breast cancer.

The PARABLE trial, led at UCLH by Consultant Therapeutic Radiographer Sairanne Wickers, is comparing more targeted proton beam therapy with standard radiotherapy, for patients who are at greater risk of long-term heart problems after radiotherapy treatment. Patient-reported side effects are an important part of the trial, as well as comparing the heart dose between photons and protons.

Oropharyngeal cancer is a type of head and neck cancer which starts in the tonsils and/or back of the tongue. It usually responds well to treatment with standard chemo-radiation and most people are cured but there can be significant late side effects including dry mouth, loss of taste and difficulty swallowing leading to reliance on feeding tubes as a consequence. The TORPEdO trial run by Dr Anna Thompson at UCLH is looking at whether PBT can reduce these late side effects, reduce the need for feeding tubes and improve patient-reported quality of life.

A team of researchers at UCLH are developing patient-reported outcome measures (PROMs) that are specific to radiotherapy and PBT.

PROMs help capture patient experience which plays a central role in evaluating the quality of care patients receive. The PROMOTE study involved clinical experts and patients with a wide range of cancers, who had undergone radiotherapy or PBT, to understand their experience and develop new outcome measures for patients having radiotherapy and PBT. The study will inform the design of future PBT studies.

PROMOTE is led by UCLH Therapeutic Radiographers Rita Simões and Danielle Fairweather-Chan and Director of the Centre for Nurse, Midwife and AHP Research (CNMAR) Dr Rachel Taylor.