A new breakthrough ultrasound technique can help transport chemotherapy drugs to the human brain, new research has revealed.
A major hurdle in treating the deadly brain cancer known as glioblastoma has been that even the most potent chemotherapy drugs cannot permeate the blood-brain barrier to reach the aggressive tumor.
But the new advance might lead to improved treatment of such malignant tumours.
The blood-brain barrier is a microscopic structure in blood vessels that connect to the brain and shield the critical organ from a vast majority of drugs and the movement of ions and molecules.
Due to this natural barrier, drugs that can be used to treat brain diseases are very limited, explained scientists from the US’s Northwestern University.
And patients with brain cancer cannot be treated with most chemotherapy agents found effective for the malignant condition in other parts of the body, as these drugs do not cross the blood-brain barrier.
In the new study, researchers conducted the first in-human clinical trial in which they used a novel, skull-implantable ultrasound device to open the blood-brain barrier.
They said this is the first trial to assess the effect of opening the blood-brain barrier using an ultrasound for administering chemotherapy in the human brain.
The results, published in the journal Lancet Oncology on Tuesday, found that ultrasound use could repeatedly permeate large, critical regions of the human brain to deliver chemotherapy that was injected intravenously.
Using the four-minute procedure, scientists could open the blood-brain barrier with the patient awake and also allow them to go home after a few hours.
The skull-implantable grid of nine ultrasound emitters can open the blood-brain barrier in a volume of the brain that is nine times larger than the device.
Opening the barrier this way was found to lead to a nearly four- to six-fold increase in drug concentrations in the brain.
In a first, the study also revealed how quickly the blood-brain barrier closes after ultrasound use.
Scientists found that most of the closing happenened about 30-60 minutes after sonication – a process that uses sound energy to agitate particles in a liquid.
The findings suggest the treatment is safe and well tolerated, with some patients getting up to six cycles of treatment.
Researchers said the new findings can help develop the sequence of drug delivery and ultrasound activation to maximise drug penetration into the human brain.
“This is potentially a huge advance for glioblastoma patients,” study co-author Adam Sonabend said in a statement.
“This opens the door to investigate novel drug-based treatments for millions of patients who suffer from various brain diseases,” Dr Sonabend added.
