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Dr. Arjun Sahgal (left) and Liora Davidson in front of the stereotactic radiosurgery machine that treated her brain tumours. She is holding a head mask that secures patients during high-precision treatment carried out with the Gamma Knife Icon.

Game-changing technology coming to Sunnybrook promises to save more lives.

Standard treatment for people with metastatic brain tumours – cancer that has spread to the brain from elsewhere in the body – has been radiation of the entire brain (whole-brain radiation). While this tactic helps control tumours, it also harms quality of life by damaging memory and other cognitive functioning.

"It’s not enough to simply treat cancer. We must be able to do it in such a way that we preserve the quality of patients’ lives."
Dr. Calvin Law, Chief, Odette Cancer Centre

A precise radiation therapy increasingly used at Sunnybrook Health Sciences Centre, called stereotactic radiosurgery (SRS), may make whole-brain radiation – and its side-effects – a thing of the past. To make that happen, Sunnybrook will install the Gamma Knife Icon, the newest and most advanced SRS system, in Sunnybrook's Odette Cancer Centre in 2016.

With the Icon, Sunnybrook's cancer experts will offer precision radiation to a broader group of patients – for instance, to people with as many as 30 brain tumours. And thanks to the Icon's design, patients can look forward to a considerably more livable experience.

"Even as recently as five years ago, it was thought that having multiple brain tumours, even one or two metastases, say from breast cancer, was a death sentence," says Dr. Greg Czarnota, head of Sunnybrook's Odette Cancer Research Program. "Now, with the new technology, we can actually cure them."

The newest version in Gamma Knife technology, the Icon works by focusing hundreds of radiation beams on a single target. Individually each beam is too weak to damage the healthy tissue it crosses on the way to its target, but at the site where they converge, cancerous tissue is destroyed. The Icon's pinpoint precision allows for the safe delivery of potent and effective doses of radiation.


After it arrives next year, the Icon will allow the Odette Cancer Centre to continue replacing whole-brain radiation with targeted radiation procedures for as many as 500 patients annually, a 30-per-cent increase.

Leading-edge technologies, like the Icon, that let doctors put down the scalpel and treat cancer non-invasively are at the heart of the centre's Cancer Ablation Therapy (CAT) program. Through non-invasive treatments, patients may experience fewer side-effects and return to their daily lives more quickly.

"The overarching goal of the program is to destroy the tumour with minimal side-effects," says Dr. Arjun Sahgal, the program head. "And that's what the Icon can do."

Unlike the previous Gamma Knife iteration, known as Perfexion, which depended on pre-treatment imaging to locate the tumour, the Icon uses real-time CT imaging to guide hundreds of gamma radiation beams toward targets in the brain with sub-millimetre accuracy.

This allows doctors to treat as many as 30 tumours in a single session, compared to the Perfexion and other targeted radiation therapies that can only treat a handful efficiently. It's a game-changer for people with cancers such as melanoma, which have a tendency to spread to the brain and often have a significant number of metastases.

The Icon's frameless design replaces the old model's metal head frame − which had to be attached to the patient's head with surgical screws to keep it motionless − with a simple custom-fitted mask that's much more comfortable for the patient and set-up is less time consuming for medical teams.

"It's only now that the Gamma Knife is not frame-based, and is now equipped with image guidance, that we really want to move into this technology. It will allow us to do treatments that we have never been able to do before," says Dr. Sahgal.

Sunnybrook isn't simply buying an Icon unit; it is actually playing a key role in enhancing the Icon ahead of its Canadian commercial release by evaluating and fine-tuning its CT image-guidance system as well as its treatment planning software.

"We're currently working on the Icon with [manufacturer] Elekta to make the technology even better before it gets to our centre," says Dr. Sahgal.

The Gamma Knife Icon project has been made possible because of a generous donation from the E. & G. Odette Foundation, which has been instrumental in bringing the technology to Sunnybrook and helping it continue to push the boundaries of medicine.

The late Edmond and Gloria Odette helped to shape cancer care at Sunnybrook. From the Gloria Odette Breast Imaging Centre to the recently renovated chemotherapy suites and Gloria Odette Pharmacy, they supported many initiatives across the hospital and worked closely with Sunnybrook leadership to make sure their giving had the greatest impact for patients. Thanks to the family's latest gift, the Gamma Knife Icon will be the first major initiative within the CAT program to be up and running.

The Icon promises to be effective in treating more than brain cancer, however. With its ability to target select areas of the brain, it may eventually be able to address depression, epilepsy, obsessive compulsiveness and essential tremor, Dr. Sahgal says. "We're going to start merging the minds that are present here at the Odette Cancer Centre, Sunnybrook Research Institute and our Hurvitz Brain Sciences Program to develop this technology for these functional disorders. That is a massive area of research and development that we're engaging in," he says.

For now, doctors at Sunnybrook are looking forward to seeing the technology roll out when it arrives next year and offering their patients best-in-class care and, most of all, hope.

"It's not enough to simply treat cancer. We must be able to do it in such a way that we preserve the quality of patients' lives and enable them to return to their loved ones quickly," says Dr. Calvin Law, chief of the Odette Cancer Centre. "The Gamma Knife Icon and the other precision technologies will allow us to achieve this critical goal."

'Hope is everything'
It’s been a long, particularly arduous fight with cancer for Liora Davidson, who was diagnosed with breast cancer in 2009. After undergoing a mastectomy, chemotherapy and radiation at Sunnybrook, Ms. Davidson once again faced bad news when she experienced seizures on a family vacation in Europe in 2011. CT scans confirmed two brain tumours, and Ms. Davidson began treatment with Dr. Arjun Sahgal.

“Altogether I had five brain procedures over the next three years, beginning with stereotactic radiosurgery (SRS),” says Ms. Davidson. A mix of treatments, including SRS, traditional radiation and brain surgeries, were used to destroy those and other tumours that developed. She is now celebrating her one-year anniversary of being cancer-free.

With the new frameless Gamma Knife Icon on the horizon, Ms. Davidson says, “I’m so happy that others won’t have to experience the head frame.” Her own experience was “not so pleasant.” The treatment required a metal head frame to be attached to her head using surgical screws. “It’s painful,” she recalls.

But she has no regrets about the procedure: “What I like about it is, it’s very specific. They don’t radiate the whole head, just the place where the tumour is.”

For future brain cancer patients, the new Icon promises faster, more effective therapy, but as Dr. Calvin Law points out, it also offers patients a better treatment experience. “It’s more comfortable for the patient. So there’s this patient-focused aspect to it,” he says. Ms. Davidson adds that, as a cancer patient, “it’s one of the most important things that the doctor has empathy and sensitivity. Most of the doctors I met at Sunnybrook are like that, and it’s so important. It makes you trust your doctor. It gives you hope. And hope is everything.”

This is the first of a three-part series on new high-precision cancer-radiation technologies coming to Sunnybrook in 2016.

This content was produced by The Globe and Mail's advertising department. The Globe's editorial department was not involved in its creation.

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