Denis Raymond hardly goes anywhere without his backpack.

But it isn't any ordinary bag: it contains a device called the Optune, which connects to wires that run along the inside of his shirt, and are attached to electrodes on his head.

The technology creates a small electromagnetic field that is directed towards the brain and is being tested for the treatment of a form of brain tumour -- glioblastoma -- which sees most patients die within one to two years of their diagnosis.

Raymond, who was diagnosed with the fast-spreading cancer more than two years ago, signed up for a trial of the device after receiving traditional treatments.

The math teacher needed to shave his head in order to attach the six electrodes, which deliver the low-intensity jolts of electricity that doctors hope are disrupting the division and reproduction of cancerous cells.

Besides lugging around the backpack, and dealing with the large batteries that last only three hours, Raymond says the device is "non-invasive" and he doesn't "feel a thing when it's on."

And in his case, the results have been positive. Patients with glioblastoma are typically given 15 months to live, but Raymond has outlived that prognosis by 13 months. He also still works as a math teacher, and has a maintained an active lifestyle that includes hiking and biking.

"The doctors, every time I meet them, they say nothing new: 'You're doing awesome. Everything is good, keep doing what you're doing,'" said Raymond.

"As it stands there has not been a change in the past year."

Raymond is one of nearly 700 patients with glioblastoma who was involved with trials of the new electromagnetic therapy.

A study funded by Novacure, which produces the Optune, found that 315 patients involved in the trials, who also underwent traditional chemo-radiation therapy, saw "significantly prolonged progression-free and overall survival."

Dr. Garth Nicholas, an oncologist at the Ottawa Hospital's Cancer Centre who led the Canadian arm of the trials, said the device gives physicians "another option" for patients with glioblastoma, which he described as "very difficult" to treat.

"This is a field where there are infrequent advances in treatment, and where it is rare to have a new development that improves the survival of patients. Anything in that regard is certainly welcome," said Nicholas.

The study indicated that the device adds on average about three months to a patient's life expectancy, results which Nicholas classified as "modest."

"It is far from being a cure, but it is another step in the right direction and some patients truly benefit," he said.

But for people like Raymond, a few extra months could make a huge difference.

"When you are looking at -- with the best treatment -- a medical survival of 15 months, three extra months is very significant," he said.

Nicholas said the device could also prove to be useful in the treatment of other forms of tumours.

"There is no reason to expect that this will not potentially work for other types of tumours, and we are on the brink of a whole host of studies that will look at this device in other cancers," he said.

With a report from CTV medical specialist Avis Favaro and producer Elizabeth St. Philip