Advancing radiotherapy technology through clinical trials

In 2011, Rob Stepney was diagnosed with prostate cancer, and in 2020 the cancer had developed to a point where intervention was necessary. Prostate cancers are commonly treated with either surgery to remove the prostate, known as a prostatectomy, or radiotherapy, which is less invasive.

Fortunately, due to regular active surveillance, as soon as Rob’s tumour had progressed, his doctors were able to set up a treatment plan without delay. Rob was invited to participate in the PACE-C clinical trial, and was recruited to the study from its Oxford site.

Thanks to a new partnership between The University of Oxford, Oxford University Hospitals Trust, and leading UK cancer care provider, GenesisCare, Rob was able to access a new cutting-edge radiotherapy machine for this trial, known as the MRIdian. The MRIdian by ViewRay at GenesisCare in Oxford was the first of its kind in the UK, and is a revolutionary approach to radiotherapy – integrating MRI technology with radiotherapy to provide targeted, localised treatment whilst potentially minimizing side effects. 

Rob completed his treatment on the MRIdian at GenesisCare as part of the clinical trial in 2021, and his involvement will form part of wider studies to assess the feasibility and efficacy of using the technology to treat cancer, particularly tumours in hard-to-reach areas. Below, Rob recounts his experience of being part of an Oxford clinical trial and accessing this state-of-the-art technology.

Rob’s Clinical Trial Experience

 Rob Stepney

After ten years of monitoring a small prostate cancer through blood tests, biopsy and imaging, the time came – as I knew it would – when something definitive had to be done. The tumour had changed from a relatively non-threatening form to one that was more aggressive.

The choice was radiotherapy or surgery. Since the long-term results of the two approaches are similarly good, I chose the less invasive option of radiotherapy. At the time, we were being inundated by the second wave of the COVID-19 pandemic, so avoiding hospital admission also seemed sensible.

At that point, my oncologist at the Oxford University Hospitals NHS Foundation Trust, Dr Ami Sabharwal, asked whether I’d agree to be part of a clinical trial comparing the standard radiotherapy treatment plan against a new approach which involved fewer but more intense sessions.

Rob speaking with the GenesisCare team

Rob undergoing radiotherapy on the MRIdian

In this new approach, the higher doses of radiation are delivered, whilst magnetic resonance imaging (MRI) allows doctors to see in real time the prostate and neighbouring healthy tissue, especially the bladder and rectum. This means that radiation delivery can be adapted so it only targets the tumour.  If the tumour moves out of target as when you breath, the treatment stops automatically until the tumour comes back into position, avoiding putting any other organs in the path of the radiation beam.

During my first treatment I realised how extraordinary it was to lie in the MRIdian machine and see my abdomen move on the scan as I breathed in and out.

Real-time imaging meant that I could lie in the scanner and see my abdomen move as I breathed

The hope for the MRIdian technology is that this new, ultra targeted approach - that precisely delivers the radiation beams to the tumour during each session - will better protect healthy tissues while allowing the maximum radiation dose to be delivered to the prostate tumour.

With any new treatment or technology research is needed to assess its benefits in terms of improved outcomes hence the need for clinical trials. When I enrolled in the study, I had a 50:50 chance of having the standard treatment. I was prepared to accept either.

As it happened, I was randomised to the new approach, which involved this machine, the MRIdian. It combines real-time scanning with a linear accelerator to deliver the radiation. As one of the research centres involved in the PACE-C trial, the University of Oxford obtained access to the machine through a partnership between the University of Oxford and GenesisCare, and to the staff expertly trained to operate it.

I was hugely impressed by the painstaking way the radiographers and oncologists marked up the images when they were planning the treatment. The cursor on the monitor (which I could see through a mirror in the scanner) moved from image to image to create contours and outline in areas to be targeted by the radiation, and distinguish them from other areas to be spared its effects.

It looked like a child’s colouring book where you can’t go over the lines – but the consequences of any inaccuracy would be more serious.

It looked like a child’s colouring book where you can’t go over the lines – but the consequences of any inaccuracy would be more serious