Wednesday, June 7

Ultrasound Trial Offers Hope to Brain Cancer Patients | Medical Investigation

A technique has been developed that could revolutionize the treatment of brain cancers and neurodegenerative diseases by temporarily allowing drugs and other substances to cross the blood-brain barrier, a structure that separates the brain’s blood vessels from the rest of its tissues.

A trial in four women whose breast cancer had spread to the brain showed that magnetic resonance-guided focused ultrasound (MRgFUS) could safely deliver Herceptin antibody therapy to brain tissue, causing the tumors to shrink.

The blood-brain barrier is a cell wall designed to prevent substances in the bloodstream, such as toxins or microbes, from entering the brain where they could cause irreparable damage to your tissues.

While in the rest of the body there are small spaces between the cells that line the blood vessels that allow the passage of small substances, in the brain these spaces are fused, which means that only water, certain gases such as oxygen, a handful of Other necessary substances and small fat-soluble drugs such as antidepressants pass.

“Many, many people have been trying many, many different ways of getting things to cross the blood-brain barrier, but it has proven extremely difficult, certainly to do it in a temporary way,” said Eleanor Stride, a professor of biomaterials at the University of Oxford, who did not participated in the investigation.

“There is a great variety of drugs that it would be good to pass on, not only for [metastatic breast cancer], but also for neurodegenerative diseases such as Alzheimer’s and other types of brain cancer “.

MRgFUS uses focused ultrasound (sound waves) to open the blood-brain barrier in specific regions by causing microscopic bubbles of contrast agent that have been injected into the patient to oscillate. These oscillations separate cells from the blood-brain barrier, allowing substances that normally struggle to penetrate the brain to pass through.

Also Read  Cravings: hormonal reality or excuse to eat on a whim?

Dr. Nir Lipsman, from the Sunnybrook Health Sciences Center in Toronto, Canada, who led the study, said: “This is a temporary process where the blood-brain barrier opens for less than 24 hours. The idea is that whatever is co-circulating in the bloodstream will have access to brain pathology (disease), where we want it to go. “

Lipsman and his colleagues had previously shown that MRgFUS could be used to temporarily open the blood-brain barrier in people with a different type of brain cancer or the neurodegenerative disease, amyotrophic lateral sclerosis (ALS), but they did not use it to transport drugs to their brains.

They have now used it to deliver the monoclonal antibody trastuzumab (Herceptin) to diseased areas of brain tissue in four patients with metastatic breast cancer.

The research, published in Science Translational Medicine, showed that the drug was absorbed by the tumors and that they shrank in response, although the trial was designed primarily to assess safety.

Importantly, none of the patients experienced any serious adverse events, and additional imaging suggested that their blood-brain barriers were resealed after 24 hours.

Blood / Brain Chart

“It has long been theorized that focused ultrasound can be used to improve drug delivery, but this is the first time we have shown that we can introduce drugs into the brain and the first time we have visualized it entering the brain.” Lipsman said. .

“Herceptin is also a huge compound, so if we can [get it in] we can pretty safely assume that we can also get other compounds that are as big or smaller in the brain with focused ultrasound. “

Also Read  Obama and Trump Enter Key Battle for Virginia Governor | Virginia

Kevin O’Neill, consultant neurosurgeon at the Center of Excellence for Brain Tumor Research at Imperial College London, said: “Many emerging therapies for brain cancer need a delivery system that not only packages and protects them, but that directs them to the correct area.

“Injecting them into the brain is one way, but this approach would be better because it is effectively non-invasive. You are opening a portal in the blood-brain barrier at the desired site. It is a step forward to open the door to other therapies ”.

Leave a Reply

Your email address will not be published. Required fields are marked *