Three innovative radiation technologies mean faster and more effective treatments for multiple types of cancer.
Photography by Doug Nicholson
Kasia Moroniewicz’s treatment last September in Sunnybrook’s new MRI-brachytherapy suite made her one of the first patients in the world to experience an innovation that has dramatically changed cervical cancer therapy.
But being the suite’s first user didn’t matter much to Kasia. What impressed her most was how the designed-in-Sunnybrook super-suite cut down her time in hospital to about two hours from an entire day and made the treatment significantly more comfortable.
“It was literally night and day,” she says. “I woke up and that was it.”
“It was literally night and day. I woke up and that was it.”
– Kasia Moroniewicz, diagnosed with cervical cancer
Before the suite was built, Kasia had gone three times for MRI-guided brachytherapy treatments to destroy tumours from her cervical cancer. The procedure involves magnetic resonance imaging of the cervix to find the tumours. This also involves the insertion of a tube-shaped vaginal applicator, where a radiation seed is positioned via a wire to emit radiation directly into the tumours.
During these first three treatments, the discomfort of having the vaginal applicator inserted for as long as eight hours, combined with the anxiety she experienced as she lay in the MRI machine, pushed Kasia, an elementary-school teacher in Brampton, Ont., to a few tears, she admits.
“You have those moments to think about what you’re going through and it feels very scary,” says Kasia, who learned last year she had cervical cancer just nine months after her first child was born. “And there are parts of the procedure that are just unpleasant. When they remove the applicator, that’s the most uncomfortable part for me.”
The new all-in-one operating room has a built-in MRI and radiation treatment bunker to treat patients who are under general anaesthetic.
“In the short span of six months, we’ve revolutionized how we treat cervical cancer,” says Ananth Ravi, a medical physicist and one of the Sunnybrook scientists who led the MRI-brachytherapy suite project. “We’ve minimized the discomfort and trauma from the treatment.”
The MRI brachytherapy initiative is among the next-level innovations now available through Sunnybrook’s Cancer Ablation Therapy (CAT) Program – a specialized unit within the hospital’s Odette Cancer Centre that uses precision therapies to target tumours without invasive surgery.
Over the last two years, the program has brought in three first-in-Canada radiation technologies, including the MRI-brachytherapy suite for gynaecological cancers. The other two are the Gamma Knife Icon, used to treat brain tumours, and the MR-Linac, which combines radiation with MRI for real-time imaging during procedures and is now in the testing phase. Each of these technologies is designed to deliver precise treatment while advancing research in cancer ablation therapy.
“Sunnybrook is in a unique position to work with the companies that make these technologies because we are recognized as world leaders in cancer care and research,” notes Dr. Arjun Sahgal, a radiation oncologist and scientist at Sunnybrook. “For the people we treat at Sunnybrook, this means access to advanced precision instruments that are in the hands of some of the best oncologists and radiosurgeons in the world.”
How has the MRI-brachytherapy suite changed the treatment of cervical cancer?
Radiation oncologist Dr. Eric Leung, the other lead in bringing the suite to Sunnybrook, describes what radiation treatment for cervical cancer was like before.
In the operating room, the patient is given an anaesthetic to go to sleep and then implanted with a vaginal applicator. She wakes up later in the recovery room and waits – often in discomfort – to be taken to the imaging department for an MRI. After the MRI is done, the patient is taken back to the recovery room where she waits while her doctors map out her treatment.
When the doctors have completed their treatment plan, she is then wheeled to the radiation bunker. A team of brachytherapy radiation therapists helps connect the brachytherapy unit to the applicator, where a high-dose radiation seed is moved into the applicator via a wire and positioned to emit radiation directly into the tumours revealed by the MRI.
“We have MRI images of where the brachytherapy applicators are in the pelvis, and we have marked out where the cancers are,” explains Dr. Leung. “The radiation seeds are connected to wires that go into the applicator tube, and they stay inside for maybe 10 seconds at a time, emitting radiation at each position in the applicator.”
Once the radiation procedure is finished, the patient is taken again to the operating room for removal of the applicator. Her last stop is the recovery room, where she will spend the final hour of a long day that can extend to as long as 10 hours.
Compare this experience to treatment in Sunnybrook’s new MRI-brachytherapy suite, where patients are anaesthetized and implanted with the applicator in the operating room, then placed immediately after in the MRI machine in the adjoining room before going back to the operating room for radiation. Patients are asleep the entire time.
“It’s a faster procedure, taking about two-and-a-half hours compared to eight to 10 hours,” Dr. Leung points out. “When the MRI machine and operating room are right in the same suite, it gives patients an optimal experience because we can do the applicator implant, wheel them into the MRI and then plan and do the treatment right away.”
According to Dr. Leung, the suite opens the way toward real-time imaging during radiation. The MRI is housed in a radiation bunker, allowing patients to be treated while they’re in the machine. “Right now, not all of our radiation equipment is compatible with MRI, which contains a very powerful magnet,” he says. “But full MRI compatibility is currently in the works.”
The suite can be used in future for other types of cancer that are typically treated with brachytherapy, including prostate, breast and gastrointestinal, notes Dr. Ravi. A number of hospitals in other Canadian provinces and in the U.S. have approached Sunnybrook about the suite, he adds.
“We’ve had queries about the suite. There is definite interest and there’s even a book that’s been published that includes a chapter on our particular design,” says Dr. Ravi. “When we first started to do this, it seemed like an outlandish idea, but in the short span of six months, we’ve revolutionized how we treat cervical cancer, so it makes sense to expand that to other types of cancer.”
First-in-Canada technology provides precise cancer treatment
First-in-Canada technology at Sunnybrook made it possible for Andrew Stewart to undergo radiation surgery, known as radiosurgery, to heat and destroy the cancer cells in his brain, and show up at his workplace the next day.
Last June, the 78-year-old entrepreneur – whose melanoma skin cancer had spread to his lung and later to his brain – came to Sunnybrook for treatment with the Gamma Knife Icon, a new frameless, high-precision tool that delivers effective doses of radiation to target tumours while sparing the surrounding healthy brain tissue. “I came out of the procedure with no side effects. I could have driven myself home,” says Andrew, who lives in Caledon, just outside Toronto. “I was back at work running my business the very next day.”
The Gamma Knife Icon is used for brain stereotactic radiosurgery treatments by focusing hundreds of low-dose radiation beams on a single tumour. The beams are emitted by 192 radiation sources set out in a conical pattern – an arrangement that causes the beams to converge when they hit their target. This allows for the delivery of a concentrated dosage of radiation that effectively destroys cancerous tissue.
Before stereotactic radiosurgery came along, tumours that had spread to the brain were generally treated with whole-brain radiation, which often affected memory and other cognitive functions because it also damaged healthy tissue. Sunnybrook had acquired the Gamma Knife Icon last November but, this year, upgraded to the fully integrated unit with a mask-based safety system.
“At that point, the unit became exactly what we wanted, which was a fully-integrated, image-guided brain radiosurgery instrument, where you no longer have to put the patient’s head into a frame,” says Dr. Sahgal, whose team consists of radiation doctors, neurosurgeons, radiation therapists and radiation physicists.
Before Sunnybrook got the new unit, patients undergoing brain radiosurgery needed to get their heads immobilized with a frame that was, essentially, screwed on to the skull. Dr. Sahgal says the screws punctured the skin and often caused pain and discomfort for patients. “Depending on the number of tumours or lesions they had, some patients would have to be in the frame for several hours,” he says. “It’s a painful experience, and patients need time for the punctures to heal.”
With the new unit, a plastic mask moulded to the patient’s face is used to keep the head still. Throughout the treatment, an infrared positioning device watches for the slightest head movement. “From an outside console, we watch in real time to make sure there’s no motion because if there is, we stop the beam,” Dr. Sahgal explains. “That’s what makes it so safe and precise.”
Sunnybrook treats an average of five people a day with the Gamma Knife Icon, he says. This work also feeds research with Sunnybrook’s medical physicists and the Sunnybrook Research Institute to improve various aspects of stereotactic radiosurgery, such as treatment planning, imaging quality and MRI response.
“We have a major research program centred around this machine,” Dr. Sahgal notes. “We are building new trials in order to ask and answer questions about the treatment of brain metastases that can only be asked and answered with the Icon. We also lead a North American Icon research group, and this is something we are very excited about.”