Courtesy of Sunnybrook (Doug Nicholson/Media Source)
In its job protecting the brain from would-be invaders, the blood-brain barrier also blocks medicines from reaching the brain. But on November 5, ultrasound zaps shook loose that tight barrier in a woman who has a brain tumor, potentially granting entry to a chemotherapy drug. The technique, which relies on tiny bubbles set jiggling by ultrasound beams, has shown promise in animals (SN: 9/27/08, p. 20). But this is the first time it has been tried on a person, says neurosurgeon Todd Mainprize of Sunnybrook Health Sciences Centre in Toronto, who led the procedure.
Mainprize and colleagues injected microbubbles, a chemotherapy drug and an imaging agent that could be visualized by a scanner into the woman’s blood. Then, targeted ultrasound beams passed through her brain, where they made the microbubbles in her blood vessels contract and expand. This jostling temporarily opened the blood-brain barrier,