Two doses of high-dose radiotherapy for prostate cancer produce no additional side effects compared to the standard five doses, according to results presented at the European Society of Radiotherapy and Oncology Congress (ESTRO 2026). Experts say this study brings us one step closer to safe and effective radiation therapy in just two outpatient visits.
The Hermes study, one of the first to randomly allocate patients to either two or five radiotherapy sessions, was presented by Dr Sian Cooper, a clinical research fellow at the Royal Marsden NHS Foundation Trust and the Institute of Cancer Research in London, UK.
Radiation therapy is one of the main treatments used to treat prostate cancer. The current standard of care in many countries is five doses of radiation therapy for localized prostate cancer. In recent years, there has been a move to deliver radiation therapy in fewer sessions and with higher doses in each session.
For patients, two treatment courses will be far less disruptive than the weeks of daily hospital visits traditionally required with radiation therapy. This convenience has clear benefits for work, leisure, family life and travel. For clinicians and health systems, fewer minutes means higher workflow throughput and the ability to get the right treatment to patients faster.
We wanted to know whether it would be feasible and safe for patients to administer comparable doses in just two treatment sessions, and to understand how it would impact potential side effects that patients might experience, such as urinary or bowel function issues. ”
Dr Sian Cooper, Clinical Research Fellow, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, London, UK
The team recruited 46 men with prostate cancer. 24 patients were treated with the standard five doses over two weeks, and 22 patients were treated with the same dose in just two sessions over eight days.
The treatment is performed with a state-of-the-art machine that combines an MRI scanner and a radiation therapy machine, allowing us to target the prostate gland with great precision while protecting the surrounding healthy tissue.
The research team found that two doses of radiation therapy using MRI-guided technology are safe and feasible, and condensing the treatment plan into smaller doses does not affect the side effects experienced by patients.
Dr Cooper explains: “Approximately one in four patients in both groups experienced moderate urinary side effects, such as increased frequency or urgency, at some point between six months and two years after treatment. There were no severe urinary tract or bowel side effects in either group. Bowel side effects were very low, with no patients in the two-session group reporting bowel side effects.
“After two years, our patients reported minimal changes in their quality of life. There were no or only minor differences in side effects experienced by patients in the two-dose group compared to the standard five-dose group.”
“Radiotherapy is one of the main ways prostate cancer can be treated and cured. It is non-invasive, minimizes the risk of bladder damage, and preserves sexual function,” said ESTRO Chairman Professor Matthias Guckenberger of Zurich University Hospital in Switzerland, who was not involved in the study.
Until recently, multiple treatments over a long period of time were thought to be most effective. This study suggests that providing treatment to patients at lower, higher doses can be effective in treating cancer and minimize the impact on side effects that patients may experience.
“Limiting treatments to two sessions reduces the need for hospital visits for patients and makes treatment easier to complete for those who live far from radiotherapy centers. Patients have peace of mind knowing that potential side effects are not affected by a more condensed treatment plan. It also reduces associated costs for hospitals and treatment centers.”
“The technology used in this trial is currently only available in a limited number of specialized centers around the world, but is growing rapidly. These results will guide how it is used and help us understand whether two doses of radiotherapy should become the new standard of care.”
sauce:
European Society of Radiation Therapy Oncology (ESTRO)
