Treating infections or tumors in the human brain is almost always a matter of surgery because of something called the blood-brain barrier (BBB) which is a sort of gatekeeper to the brain.
A new clinical trial of patients with glioblastoma (a kind of brain cancer tumor) shows that bursts of high intensity sound can temporarily disable the BBB allowing chemotherapy drugs to attack the tumor(s).
The function of the BBB is to protect the delicate brain. It consists of three major components.
One, limited spacing between endothelial cells (a thin layer of cells coating the walls of blood vessels) which limits the amount and kind of material which passes through the wall to the cells.
Two, proteins which actually transport the chemicals to the brain are specific to just the kinds of things (such as glucose - blood sugar) and ketones which provide an alternative source of energy. Also passed are fatty acids and some amino acids.
Three, a set of enzymes which attack and alter undesired blood contents.
A clinical trial just published in the Science Translational Magazine (AAAS Science.org) shows that many tumors such as a glioblastoma which is very aggressive, can now be treated using a combination of traditional chemotherapy and sound.
Researchers have found that a pulsed ultrasound device implanted in the skull and activated during treatment sessions can interrupt the effectiveness of the blood-brain barrier, allowing the chemotherapy to cross from the bloodstream to the brain and attack the tumor.
The system called SonoCloud was shown by MRI studies to interrupt the BBB at acoustic pressure levels up to 1.1 megapascals without any adverse effect on the brain tissue in radiologic or clinical tests.
Details aside, the important point for patients and families (as well as the few doctors who I know actually read this blog) is learning that there IS, or soon will be an alternative to brain surgery to treat cancers which could be treated with chemotherapy if they were in a less well protected part of the body.
No comments:
Post a Comment