Dr Helen McNair

29 November, 2019

The Lead Research Therapeutic Radiographer at The Royal Marsden and Team Leader in Translational Therapeutic Radiography at the ICR explains how the pioneering MR Linac is being used to treat patients as part of research into its capabilities

What does the MR Linac do?

It combines two technologies – an MR scanner and a linear accelerator – to precisely locate tumours, tailor the shape of X-ray beams in real time and accurately deliver radiation to moving tumours. Together, The Royal Marsden and the ICR were the first centre in the UK to install the machine in November 2016 – thanks to a £10-million grant from the Medical Research Council, with additional support from The Royal Marsden Cancer Charity.

Dr Helen McNair, Lead Research Therapeutic Radiographer at The Royal Marsden and Team Leader in Translational Therapeutic Radiography at the ICR

What is your role in the MR Linac team?

Initially, I helped to co-design the MR Linac suite and develop the research protocols to investigate the benefits of the machine. Now it is in clinical use, I’m involved in developing the processes and workflow for patients.

I was recently awarded a Senior Clinical Lectureship by the NIHR, enabling me to lead a new study to find out how we can train staff to deliver a technique known as real-time adaptive radiotherapy.

How does the MR Linac differ from a regular radiotherapy machine?

At the moment, we use MRI scanners to help plan patients’ radiotherapy. This is done several days before treatment starts, and the resulting image helps us pinpoint where in the body we need to aim the beams. However having a scanner as part of the MR Linac means we see the tumour in real time as the patient has treatment and can direct the radiation far more accurately.

How does this technology benefit patients?

The locations of tumours and organs can change over time. For example, a tumour in the lung will move up and down as a person breathes, while a tumour in the rectum or prostate may move from day to day, depending on what the patient has eaten or how full their bladder or bowel is. The precision of the MR Linac allows us to adapt the treatment each day to better target these types of tumours so we can safely deliver higher doses of radiation, making radiotherapy more effective, with fewer side effects.

How many patients have been treated on the MR Linac so far?

We treated our first patient in September 2018 as part of the PRISM trial for prostate cancer. Since then, we have continued treating patients on this trial, as well as opening trials for rectal, bladder and cervical cancers. We have also tested the imaging technology on volunteer patients, including one with a paediatric brain tumour in preparation for treating children with cancer in the future.

What does the future hold?

Some cancers – prostate and breast, for example – respond most effectively to large doses of radiation delivered over a short period. The MR Linac’s precision could one day make it possible for us to cure many cancers in a single treatment. That’s incredibly exciting, and so positive for our patients and their families