A pioneering trial to test if men with prostate cancer can safely receive radiotherapy in two large doses rather than smaller doses over five sessions has opened at The Royal Marsden NHS Foundation Trust. Image Dr Alison Tree, Consultant Clinical Oncologist at The Royal Marsden The HERMES trial will randomise patients to one of two treatment regimes, a standard course of five doses over ten days or two higher doses over eight days. All patients recruited to the trial will receive their stereotactic body radiation therapy (SBRT) treatment on the pioneering MR Linac machine which combines two technologies, an MRI scanner and radiotherapy Linear Accelerator. Dr Alison Tree, Consultant Clinical Oncologist at The Royal Marsden, and leading the trial said: “We have considerable experience with five-dose SBRT so delivering treatment over two, larger doses is the next step. Previous work has shown it is theoretically possible to deliver two fraction SBRT on the MR Linac and previous studies have shown internal radiotherapy (brachytherapy) administered in two fractions to be a safe option for patients with localised prostate cancer. “We hope that this study will give us a treatment regime that can safely treat men with fewer visits to hospital, allowing them to get on with their lives.” The HERMES trial is funded by JP Moulton Foundation.