(Nova Scotia Health - image credit)
Two Halifax neurosurgeons performed a successful operation this week using a drug that promises a long-awaited advance in brain surgery.
In a four-hour procedure, Dr. Sean Barry and Dr. Adrienne Weeks removed a glioblastoma, a tumour, from a female patient's brain Thursday.
They were guided by a drug called 5-ALA and a fluorescent light. It is the first time the drug has been used in brain surgery in Nova Scotia.
"I think, for the first case, it couldn't have gone better," said Barry following the surgery.
Glioblastoma is the most common brain tumour Barry and Weeks see in practice.
"They're aggressive tumours, and they are rapidly dividing tumour cells. Unlike solid organ tumours, these are tumour cells that are infiltrating in the brain," Barry said.
"The issue is with margins of the tumour. It's very difficult to distinguish tumour tissue from healthy brain tissue."
Dr. Sean Barry is shown operating using a surgical microscope.
Weeks described the main area of a glioblastoma as bleeding a lot, looking raw, and red or grey in colour.
"The texture can be more 'suckable;' it's not quite the same tenacity as normal brain," she said. "But as you get out to the edges of these tumours, they can start to look a little bit more like normal brain."
Bright white light
Surgeons working on brain surgery typically use a high-magnification surgical microscope underneath bright white light.
Although the goal is to remove as much of the tumour as possible, if there is difficulty in distinguishing the edge of the tumour a surgeon may leave a wider margin to avoid taking out healthy brain tissue.
"Particularly when you're close to important structures that you don't want to hurt, things that control people's ability to move or talk, having an ability to know whether that's still tumour or whether that's viable brain, I think, is key in helping us do surgery safely," said Weeks.
That was what inspired Weeks to apply for the first provincial use of the 5-ALA drug, which goes by the trade name Gleolan.
Weeks said there is "mounting evidence" that removing the entire tumour helps a patient's chances of survival. A full randomized trial has not been done, but she said from a surgical standpoint patients do better.
"The more of this tumour that we can safely take, the better people will do, or their outcomes will be improved," she said.
The patient drinks the drug a few hours before surgery. It is described as tasting like warm, fizzy orange juice.
Drug absorbed into brain cells
The drug is absorbed into the brain cells. The tumour cells absorb the drug faster than the healthy brain cells, and under fluorescent light they emit a pink glow. The healthy brain glows blue.
The surgeons alternate between working under white light and under fluorescent lights.
"It's exciting from a surgical standpoint because these tumours are notoriously difficult to treat. There hasn't been a lot of surgical advances in many years, so this is the first advance in surgical technique in some time," Barry said.
Dr. Adrienne Weeks of Nova Scotia's health authority is shown operating on a patient.
Barry said about 25-30 such brain surgeries are done by the surgical group each year in Nova Scotia.
Health Canada approved the drug in Canada in September 2020. It is expensive, costing up to $3,000 per use.
Weeks said she hopes to use the drug in future and the next step is to ensuring that the funding is in place to pay for the medication.
"I think this is our first trial run. Do we like it? Is it helpful? And I think Dr. Barry and I both have positive things to say about it," she said.
Barry said he also thought this surgery was ultimately safer.
"In spite of this cost and the difficulty in accessing it I think everyone appreciated that in the end it is in the best interest of the patient," he said.
Barry said there was a small learning curve in adapting to working under fluorescent light, but he and Weeks caught on "quite quickly" and it's possible the surgery was done faster than it would have been under white light.
Susan Marshall, the CEO of the Brain Tumour Foundation of Canada said it was "great news" that surgeons in Nova Scotia are starting to use the drug in their work.
"We've been aware for quite some time about this drug and the benefit that it can have to assist neurosurgeons in successfully removing brain tumours," she said. "With limited treatment options, such a new advancement would bring hope to patients facing this often devastating disease."
Marshall added that an estimated 27 Canadians receive a diagnosis of a primary brain tumour every day.
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