Canadian Doctor At Sunnybrook Toronto First In World To Break Blood-Brain

This surgery was used on patients with glioblastoma-an aggressive type of brain tumor-to deliver chemotherapy drugs directly into the brain.

A recent study by Gerhard Leinenga and Jürgen Götz from the Queensland Brain Institute in Australia further corroborated Hynynen’s research, demonstrating opening the blood-brain barrier with focused ultrasound reduced brain plaques and improved memory in a mouse model of Alzheimer’s disease.

While this barrier helps protect the vessels from toxins and infections, it also prevents doctors from effectively treating brain diseases and tumors in patients.

In order to get medication directly to the site of the patient’s malignant brain tumour, the scientists needed a way of getting past the blood-brain barrier.

But neuroscientists at Sunnybrook Health Sciences Centre have found a non-invasive solution.

This patient treatment is part of a pilot study of up to 10 patients to establish the feasibility, safety and preliminary efficacy of focused ultrasound to temporarily open the blood-brain barrier to deliver chemotherapy to brain tumors.

Testing, carried out on animals, has yielded good results.

Bonny Hall is the first patient to undergo the technique.

Hall is a mother, grandmother and business owner who recently learned that the benign brain tumour she has lived with for eight years had started to grow quickly and is malignant.

Although the tumour caused no pain, Hall experienced what she described as “little blips”, or small 10- to 20-second seizures during which she would feel “spaced out”. The tumours are often hard to treat because they spread out in a web, and can’t be completely removed with surgery.

Dr. Todd Mainprize, lead researcher of the Sunnybrook study, said that even though chemotherapy can be used to treat the remaining cancer cells following the surgical removal of the glioma, only 25 percent of the medication actually reaches the patient’s brain. That is in part why brain cancer survival rates are so low, he says.

“Frankly speaking, our ability to treat this type of tumour, glioma, is not good”, he told CTV News.

The non-invasive technique involves injecting harmless gas microbubbles into the bloodstream, then using a high-intensity ultrasound beam onto the tumour to cause the bubbles to vibrate and tear apart the proteins around capillaries, thus allowing the drug into brain tissue. The procedure was performed last week for the very first time on a 56-year-old female patient with a brain tumor. To ensure it worked, the chemotherapy drug was marked with a chemical tag to make it visible on MRI scans. As the research team watched, the chemotherapy drug moved through Bonny’s blood vessels into her tumour.

Mainprize said the procedure went exactly as they had hoped. “It will give hope to patients who have no hope”.

Medical researchers have long sought an answer to bypassing the blood-brain barrier, a layer of tightly packed cells that surrounds each of the blood vessels of the brain.

If the technique is determined to be safe and replicable, doctors will soon be sending drugs to treat diseases that affect the brain straight to where they’ll be most effective, instead of applying a big dose to the body and hoping it works.

Here in the S-wing of Toronto’s Sunnybrook Hospital, Mainprize and his research team accomplished on Thursday what no one in the world has ever done before: Using focused ultrasound waves, they have opened the human blood-brain barrier, paving the way for future treatment of an array of now impossible or hard-to cure-illnesses – from brain cancer to certain forms of depression, stroke, Parkinson’s disease and Alzheimer’s disease.