MR Linac - first ever treatment

The Royal Marsden and The Institute of Cancer Research, London, have delivered the first ever treatment in the UK using a Magnetic Resonance Linear Accelerator (MR Linac) machine.

The MR Linac is the first technology in the world to simultaneously generate magnetic resonance images and deliver X-ray radiation beams — allowing radiotherapy to be adjusted in real time and delivered more accurately and effectively than ever before.

The ability to target tumours with radiation beams in real time will be particularly effective for cancers that change position through breathing, bladder filling or bowel changes and should reduce the side-effects for the patient. For example tumours in the prostate, lung, bladder and bowel would be targeted in real time – allowing the radiation beams to be adjusted with enhanced precision during the course of treatment.

The patient received radiotherapy treatment on the MR Linac as part of the PRISM clinical trial, which is the first of its kind in the UK. Previously people have only had an imaging scan as part of early trials to calibrate the pioneering machine.

Professor Uwe Oelfke, Head of the Joint Department of Physics at The Institute of Cancer Research, London, and The Royal Marsden, who leads the joint MR Linac project, said: “For decades the radiation oncology community has dreamed of the day when we could see what we treat in real time just as our surgical colleagues do, and we are excited that this day has arrived. Radiotherapy is important to the treatment of around 40 per cent of the people who are cured of cancer. But if we want to fully unlock the potential of radiotherapy by making it even more precise in targeting the cancer and avoiding healthy tissue, we need to be able to see a patient’s tumour while we deliver the radiation treatment. The MR Linac will make this possible.

“The ICR and The Royal Marsden have made world-leading advances in radiotherapy through our research and we expect the MR Linac to allow us to make another step change in improving cancer treatment. This trial is for prostate cancer but we anticipate the MR Linac will help us improve radiotherapy for a wide range of cancers, including hard-to-treat forms such as lung and pancreatic cancer.”

The breakthrough has been six years in the making. In 2012, a team at Utrecht Medical Centre and the company Elekta, which makes the MR Linac, and MR partner Phillips began to form an international consortium. The ICR and The Royal Marsden formed one of the seven founding members. The aim was to provide an evidence-based introduction of the MR Linac to the medical community, and to support the advancement of the technology. In 2015, almost 12,000 tonnes of earth were excavated to create a bunker – large enough to hold 24 double decker buses – to house the machine, and in 2016 the five tonne magnet for the scanner was lowered in.

The installation of the MR Linac was made possible by a £10m grant from the Medical Research Council to The Institute of Cancer Research (ICR), with additional support from The Royal Marsden Cancer Charity.

Dr Alison Tree, Consultant Clinical Oncologist at The Royal Marsden and Team Leader in Uro-oncology Clinical Trials at The Institute of Cancer Research, London, who is leading the PRISM clinical trial, said: “Prostate cancer responds most effectively to large doses of radiation delivered over a short period. However, because the prostate lies close to the rectum, high doses risk damaging the rectum and increasing side-effects.

“With the MR Linac we can better target the prostate while avoiding the rectum, so we can safely deliver higher doses of radiation. It is possible that this groundbreaking precision will one day make it possible for us to cure prostate cancer in a single treatment.”