Monoclonal antibody treatments encourage the body’s natural immune system to attack cancer cells. However, applying this therapy to the brain has proven very difficult due to the blood-brain barrier. An IEEE Spectrum article noted that MRI and ultrasound could be the key to delivering cancer drugs through the barrier to help fight tumors.
In a recent study, scientists used focused ultrasound beams guided by MRI to temporarily make the blood-brain barrier more permeable. Four patients with metastatic breast cancer received 20 total treatments of a monoclonal antibody treatment called Herceptin. The researchers employed a hemispheric helmet equipped with 1024 ultrasound transducers to deliver the ultrasound and adjusted the voltage in individual transducers to account for variations in skull thickness.
While receiving targeted ultrasound, the patients also got an infusion of lipid-based microbubbles, which prevented damage. Though the concept of employing ultrasound to increase the permeability of the blood-brain barrier dates back to the 1950s, it wasn’t until high-resolution MRIs came along that hope was given to this method.