Getting an ultrasound may help patients combat a cancer diagnosis.
Brain cancers are infamous for being difficult to treat since most chemotherapy drugs cannot break through the blood-brain barrier, a microscopic cell layer that protects the brain from toxins. While the barrier does a good job shielding the brain from toxins and pathogens, it also acts as a barricade for many medications. However, researchers are now saying they can use an experimental ultrasound device to temporarily open up that barrier and send more chemo to fight brain tumors.
A new study highlights how the method has overcome different barriers when treating brain cancer. Even when a drug reaches the brain’s circulation, irregular blood vessels in and surrounding tumors result in uneven drug delivery with low concentrations in certain areas of the tumor.
If a drug makes it through the irregular blood vessels, thick tumorous tissues normally block its path toward the cancerous cells. Arvanitis led the study with Dr. Vasileios Askoxylakis at Massachusetts General Hospital to examine the effectiveness of ultrasound on tumorous areas. The method has already proven quite effective for fighting tumors, allowing it to enter phase I of clinical trials.
Ultrasound technology has resulted in a four to six-fold increase in chemo drug concentrations in patients’ brains. The scientists observed this increase with two different chemotherapy drugs, carboplatin and paclitaxel. These drugs are not normally used for treating brain tumors since they normally can’t penetrate the blood-brain barrier.
For the research, doctors removed the glioblastoma in patients surgically – the most common cancerous brain tumor found in adults – and then inserted an ultrasound grid of nine emitters into their skulls. Within a couple of weeks after surgery, patients were put on chemo treatment to kill any leftover malignant cells in their brains.
The ultrasound grid, designed by Carthera, opened the blood-brain barrier in critical areas of the brain. This enabled the paclitaxel drug to penetrate. The entire ultrasound process takes around 4 minutes and can be performed while the patient is awake. Patients can go home after a few hours.
During the process, when the bubbles encounter an ultrasound wave, they start vibrating. This pushes apart the blood-brain barrier’s cells, allowing the drug to easily penetrate the brain walls. The barrier fully closes within an hour.
The blood-brain barrier reestablishes quickly after the procedure, while most of its integrity is restored within an hour. The findings were published in The Lancet Oncology journal earlier this month.
It is important to note that the treatment was well-tolerated and safe, as per the researchers. Some patients received a total of six treatment procedures for their tumors. The key findings from the report have established the foundation for a clinical trial where patients will be given a combination of carboplatin and paclitaxel to see if the treatment extends their survival.
Since the results are so promising, researchers are hopeful that the ultrasound technique could help deliver various types of drugs to the brain. This can open the door to investigating unique drug-based treatments for countless patients struggling with different brain diseases.
Sources:
Ultrasound Breaches Blood-Brain Barrier, Helping Drugs Fight Tumors
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