A new sound wave technique can help treat a deadly brain cancer called glioblastoma in just four minutes. The groundbreaking report was published May 2 in the journal Lancet oncology and demonstrates the results of a phase 1 human clinical trial with 17 patients.
In the trial, patients underwent surgery to resect or remove their tumors and were implanted with an ultrasound device. The device inside the skull opens the blood-brain barrier, repeatedly using sound waves to penetrate the barrier and reach the brain tumor. The IV chemotherapy can then reach the neurological tissues where the cancer can grow.
Treating this type of brain tumor, which has a 6.8 percent survival rate within the first five years of diagnosis, with the most powerful types of chemotherapy is difficult. Stronger cancer drugs usually cannot penetrate the blood-brain barrier. The blood-brain barrier acts as a line of defense, forming an extra wall around the brain to prevent toxins and pathogens from entering such a crucial area of the body. However, the repertoire of drugs that can be used to treat brain diseases is very limited. In 2014, scientists discovered for the first time that sound waves could be used to penetrate the blood-brain barrier, and this study builds on that discovery.
[Related: Understanding glioblastoma, the most common—and lethal—form of brain cancer.]
“This is potentially a breakthrough for glioblastoma patients,” co-author and Northwestern University neurosurgeon Adam Sonabend said in a statement.
The study reports that the use of a new skull-implantable grid of nine ultrasound emitters made by French biotech company Carthera can open the blood-brain barrier in a brain volume nine times greater than small implants of a single ultrasound emitter. originally used. This helps significantly in treating a large region of the brain along with the cavity that remains after glioblastoma tumors are removed.
This is also the first study to show how quickly the blood-brain barrier closes after being opened by ultrasound. It closes in the first 30 to 60 minutes after communication. and this will help scientists to optimize the order of drug administration to allow better penetration into the brain. The procedure to open the blood-brain barrier only takes four minutes and is done while the patient is awake. The new results show that the treatment is safe, well tolerated, and some patients received up to six cycles of treatment.
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Opening of the blood-brain barrier led to an approximately four- to six-fold increase in drug concentrations in the human brain. The team observed this increase with two chemotherapy drugs called paclitaxel and carboplatin. These drugs are generally not used to treat patients with glioblastoma, because they do not normally cross the blood-brain barrier under normal circumstances.
According to Sonobend, the current chemotherapy used for glioblastoma (temozolomide) crosses the blood-brain barrier, but it is weak. Sonabend also said that previous studies that injected paclitaxel directly into the brains of patients with these tumors had promising signs of efficacy, but the direct injection was associated with toxicity such as brain irritation and meningitis.
A Phase 2 clinical trial is already underway. “While we have focused on brain cancer (for which there are approximately 30,000 gliomas in the US), this opens the door to investigate new treatments based on in medicines for millions of patients suffering from various brain diseases,” said Sonabend.