Cancer Innovation Sunnybrook Magazine - Spring 2016

High-tech tool will target tumours with extraordinary precision

Calvin Law

Dr. Calvin Law says the new MR-Linac equipment will “allow patients to have treatments faster, better and with resulting gains in quality of life.” (Photograph by Doug Nicholson)


Sunnybrook is part of an elite global team working with new image-guided radiation technology that raises the stakes in fighting the most hard-to-treat cancers


Soon, a revolutionary, six-tonne piece of machinery will be lowered through the roof of Sunnybrook’s Odette Cancer Centre and into a specially constructed radiation treatment bunker. It will be a huge undertaking – the equipment is so massive the roof is the only way in.

But the effort will be more than worth it. Bringing the new hardware, known as an MR-Linac, on stream will be a major leap forward in the treatment of cancer. The equipment will save more lives by precisely targeting even the most elusive tumours with high-powered radiation.

The MR-Linac is the world’s first machine to fuse a radiation delivery system (known as a linear accelerator) with a magnetic resonance imaging (MRI) machine. The Odette Cancer Centre will be the first Canadian site to have the technology. Sunnybrook is part of a seven-member international consortium hand-picked for their expertise by Elekta and Philips – the MR-Linac’s manufacturers – to refine, test and use the machine to treat patients.

The MR-Linac Dream Team
Sunnybrook is one of the founding members of the consortium that also includes:

  • Christie NHS Foundation Trust (Manchester, U.K.)
  • University Medical Center Utrecht (Utrecht, Netherlands)
  • University of Texas MD Anderson Cancer Center (Houston, U.S.)
  • Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital (Amsterdam, Netherlands)
  • Froedtert & Medical College of Wisconsin Cancer Center (Milwaukee, U.S.)
  • The Institute of Cancer Research/ Royal Marsden NHS Foundation Trust (London, U.K.)

The MR-Linac carries out high-definition imaging of tumours in real-time during radiation therapy. This will allow Odette Cancer Centre specialists to target tumours with extraordinary precision – even as a tumour moves inside the body – and to quickly see the radiation’s effect on the tumour.

With the technology, doctors will be able to more effectively treat a host of cancers that were previously hard to tackle. “It’s very exciting for pancreatic cancer, esophageal cancer and other cancers where we have been limited in the way we can treat them with radiation because the tumours actually move,” says Dr. Arjun Sahgal, head of the Odette Cancer Centre’s Cancer Ablation Therapy Program.

“It’s also exciting for brain cancer, where real-time understanding of tumour change would help spare healthy tissue from radiation,” Dr. Sahgal says, adding that the MR-Linac may also allow some breast cancer patients to avoid surgery. The MR-Linac’s more detailed real-time images of tumours and surrounding tissue mean doctors will be able to more precisely target the cancer and fine-tune the amount of radiation delivered. As they monitor how tumours are responding to radiation, they can adjust treatments as they go, potentially resulting in fewer treatment sessions and side effects.

“The MR-Linac will help us better understand the mechanisms of tumour response during actual treatment, in a sense making a tumour visible in a way that has not been possible before,” says Dr. Gregory Czarnota, head of radiation oncology at the Odette Cancer Centre and an international research leader in brain and spine cancer.

As part of the global consortium testing and refining the MR-Linac, Sunnybrook will work with the other members to prepare the machine for the first human clinical trials. “It’s a global consortium of medical physicists, research scientists, radiation oncologists, partnering together all across the world with the common goal of advancing the entire field of MRI-guided radiation,” says Dr. Sahgal.

Sunnybrook is developing the machine’s applications for brain cancer. “We are the lead site for the consortium to develop applications of the MR-Linac for glioblastoma, the most common malignant brain tumour in adults,” says Dr. Sahgal. “We have a protocol that’s looking at advanced imaging for primary cancers of the brain as a first step, and we’re going to have a clinical trial that’s geared toward adapting the radiation dose using the MR-Linac each day as we treat primary brain tumours.”

Dr. Calvin Law, chief of the Odette Cancer Program, says Sunnybrook’s “responsibility as an academic centre is not only to deliver the standard of care, but also to always ask the question: ‘How can we improve the system?’ We have already been making the most out of the technology we have. This next level will combine existing innovation with a new way of doing things and allow patients to have treatments faster, better and with resulting gains in quality of life.”

After the MR-Linac is installed, there will be testing and further treatment protocol development. The team hopes to be treating patients by 2017.

“It’s a paradigm shift. It’s not just a new machine for radiation therapy; it’s more than that,” says Dr. Brian Keller, a Sunnybrook medical physicist and physics lead for the MR-Linac project. “It has very good imaging so we can hone in on where the tumour is, and because we can do that, we can deliver a higher dose, using fewer treatments, and perhaps eliminate surgery that some patients would need in the future.”

There’s great anticipation as a cancer treatment of the future arrives – and, with it, new hopes for patients at Sunnybrook and beyond.

MR Linac

Click here to view a plain-text version of the infographic

How the MR-Linac Works

  • Radiation Beam: Because the MR-Linac uses real-time imaging, doctors can direct the radiation beam at tumours with unprecedented precision, even as the tumour moves or changes as it is damaged by the radiation.
  • Treatment bed: As with standard MRI machines, the MR-Linac patients lie on a bed that moves into the imaging/treatment chamber.
  • Magnetic field: The MR-Linac’s developers overcame a major engineering hurdle by creating a machine that can simultaneously visualize tumours with high-resolution magnetic resonance imaging and treat them with radiation

Illustration by Tonia Cowan