New radiation machine targets cancer with pinpoint accuracy — even as the tumour moves during treatment
Dr. Miller MacPherson accepts delivery of the MR-Linac radiation therapy system.
A new radiation therapy system will empower The Ottawa Hospital’s radiation oncology team to target cancer with unprecedented accuracy — even as the tumour moves inside the patient’s body during their treatment session.
On July 13, our Cancer Centre accepted delivery of the MR-Linac, the world’s first machine to combine diagnostic-quality magnetic resonance imaging (MRI) with a radiation machine called a linear accelerator (linac). The MRI finds the tumour, and the linear accelerator fires a radiation beam to shrink it.
“It’s really an engineering marvel to bring these two technologies together,” says Dr. Miller MacPherson, Head of Medical Physics at The Ottawa Hospital Cancer Centre.
Hitting a moving target
Radiation therapy is a powerful way to treat a variety of cancers — including prostate, lung and breast cancer — but it can also damage healthy tissue. That’s why medical radiation technologists must be careful to only treat the tumour and not the surrounding area.
The problem is that tumours tend not to stay in one place. Even the simple act of breathing in and out is a big driver of internal movement and can cause a tumour to shift within a patient’s body in the middle of a treatment session.
But the MR-Linac automatically tracks the tumour in real time while the radiation beam is on, preventing harm to healthy tissue.
“We can deliver a radiation treatment that’s exactly personalized for the patient on that day,” says Dr. MacPherson. “We will be able to treat more accurately, and we may be able to treat areas of the body that we couldn’t treat with radiation before because it was just too risky, given the healthy tissue near the tumour.”
An early adopter
Our Cancer Centre is now home to the third MR-Linac system in the province, following two centres in Toronto, making us one of the first adopters in the country. This engineering marvel has come to the nation’s capital thanks to the generous support of The Ottawa Hospital, Cancer Care Ontario, community donors and industry vendor Elekta, which supplied the MR-Linac.
