The HERMES study at The Royal Marsden showed promising results using just two higher-dose radiotherapy treatments with no increase in side effects for patients.
In the trial, patients received radiotherapy treatment in two higher doses over eight days, which was shown to be as safe and effective as the current standard of five radiotherapy sessions over two weeks. This study used advanced MRI-guided radiotherapy technology on the magnetic resonance linear accelerator (MR Linac), a state-of-the-art piece of hospital equipment, which the Charity helped to fund.
Key points
- The HERMES study tested whether the same overall dose of treatment could be delivered safely to patients with localised prostate cancer in just two sessions over an eight-day period instead of a usual five doses over two weeks
- Radiotherapy was delivered during the trial using advanced MRI-guided technology on the state-of-the-art MR Linac, equipment at the hospital which was funded with support from the Charity
- Patients showed no increase in side effects, such as severe changes to urinary and bowel function
- The study is the first in the world to use MRI-guided adaptive radiotherapy to treat patients with localised prostate cancer in just two sessions of radiotherapy.
The research was led by Dr Alison Tree, Consultant Clinical Oncologist at The Royal Marsden and Leader of the Uro-oncology Clinical Trials Group at The Institute of Cancer Research, London (ICR). The results were presented in May 2026 at the Congress of the European Society for Radiotherapy and Oncology (ESTRO) in Stockholm.
More precision to minimise side effects for patients
Radiotherapy is one of the main ways to treat localised prostate cancer. Currently, many hospitals will treat patients with five sessions which are delivered over two weeks.
The HERMES study used the MR Linac which combines MRI images with radiotherapy. This ensures the treatment given to patients is achieved in a highly precise way directly to the cancer cells, helping to protect surrounding healthy tissue.
Damien, a 64-year-old delivery driver from London, was diagnosed with prostate cancer in 2023 and joined the HERMES trial at The Royal Marsden.
“I went through radiotherapy without pain or side effects. I can honestly say I haven’t had a bad day; my life didn’t stop in the way I thought it would.”
Together with the ICR, The Royal Marsden was the first hospital in the UK to treat patients with the MR Linac in 2018. This modern hospital equipment was funded by a £10 million grant from the Medical Research Council to the ICR and supported by The Royal Marsden Cancer Charity. Your donations help to ensure patients continue to receive world-leading treatment and care.
Results from the HERMES study
The HERMES study showed that delivering treatment to patients in fewer, higher doses of radiotherapy is as effective in treating the cancer and as safe for patients, who showed minimal side effects during the trial.
Having a two-session course instead of treatment in five doses over two weeks would mean less time in hospital for patients and fewer trips away from family or work. A shorter treatment course would also mean clinicians could provide patients with more effective treatment sooner.
Next steps
Larger studies are now needed to confirm the findings from the HERMES study. The research team aim to run further randomised trials to test any patient side effects that occur later on after treatment before this approach could become a widely used standard of care.
The HERMES trial was funded by the Jon Moulton Charity Trust and also received support from the UK National Institute for Health and Care Research (NIHR) Biomedical Research Centre at The Royal Marsden and the ICR.
The Charity continues to support the expansion of radiation-based research at The Royal Marsden by funding research roles and hospital equipment, improving radiotherapy care for patients.
Making breakthroughs happen
Your generosity helps us continue to support research and fund hospital equipment to provide patients with world-leading treatment and care. Groundbreaking work at the hospital is optimising treatment for patients with minimal damage to healthy tissue by using the latest medical equipment, such as the MR Linac and Radixact Linac.
With your support, we’re helping people with cancer to live well throughout their treatment and beyond. Read more about how your incredible donations support prostate cancer patients across the UK and around the world:
- Supporters of the Charity help to fund the latest hospital equipment. This includes a state-of-the-art da Vinci Xi robotic surgical system which is used to treat patients with prostate cancer. The Royal Marsden has become the most comprehensive centre for robotic cancer surgery in the UK, ensuring patients with prostate cancer – and other cancers too - have access to the latest techniques and technology
- With your support, we’ve also funded two CyberKnife radiotherapy machines at The Royal Marsden. The CyberKnife delivers highly precise stereotactic body radiotherapy (SBRT) and was used in the PACE-B trial, the first global randomised trial of its kind. Results showed this treatment had 96% effectiveness in under 2 weeks, so that some patients could reduce their treatment time from 4-8 weeks (with conventional radiotherapy) to 2 weeks or less.
- The BARCODE-1 trial at The Royal Marsden aims to develop a screening test that could diagnose prostate cancer earlier than the standard prostate-specific antigen (PSA) test by using a patient’s saliva sample
- The ADHERE programme offers prostate cancer patients structured physical exercise for support throughout their treatment to help improve quality of life
- Abiraterone, a type of hormone therapy drug, is used to treat prostate cancer across the world today and was first developed by The Royal Marsden and the ICR
- Understanding why certain people may be at more risk of prostate cancer is another important aim of research which you’ve helped us to support in the PROFILE study.
Progress in cancer treatment, thanks to partnership
Our partnership with Nationwide Building Society is supporting groundbreaking research to develop new life-saving cancer treatment. Through its social impact strategy Nationwide Fairer Futures, Nationwide is funding 30 specialist research staff at The Royal Marsden, including Dr Alison Tree. We’re helping over 100 clinical trials to run across different treatment types, including radiotherapy. We are incredibly grateful to Nationwide for their support.
Our work is only possible with your support
Together, we’re making research breakthroughs happen to revolutionise the way cancer is diagnosed and treated. Your support is improving treatment and care for people with cancer, thanks to life-changing research at The Royal Marsden.
Find out how to donate today.