Lasers Can Improve Chemotherapy Delivery in Brain Cancer

Laser system allows temporary window in blood-brain barrier to effectively target glioblastoma.

Numerous chemotherapy drugs have previously been found ineffective treating patients with glioblastoma, however, recent research has shown that a laser system that kills brain tumors can open up a temporary window, allowing for drugs to pass through to the brain.

A team of researchers from the University of Florida Health found an additional benefit for the laser system. Chemotherapy drugs are able to pass into the brain for up to 6 weeks once the temporary window in the blood-brain barrier is opened.

"This gives us a very significant window of time to give chemotherapy," said co-lead study author David D. Tran, MD, PhD. "We will be able to test a lot of drugs for effectiveness."

The study was conducted at the Washington University School of Medicine and the results were published in PLOS ONE.

Researchers used a probe no bigger than a pencil as the laser that heats up the surrounding area of the tumor disrupts the blood-brain barrier without killing neurons. This procedure is called MRI-guided laser ablation.

During the pilot trial, researchers used 14 patients with brain tumors to perform the laser ablation procedure followed with the chemotherapy drug doxorubicin, which is normally blocked by the blood-brain barrier.

By creating a leaky barrier, the procedure allows the immune system to recognize the tumor more easily to gain access. The final results for the clinical trial are expected within a year.

Although prior research has shown that laser ablation could enable the immune system to attack tumors, the cancer cells can still find ways to hide from the immune system.

Researchers believe that if they combine laser ablation with a PD-1 inhibitor drug, it could stop tumors from avoiding the immune system. This clinical trial should be completed in 2 years.

Currently, there are clinical trials for treatments that improve delivery for newer chemotherapy drugs with more precise targets, fewer side effects, and that do not cross the blood-brain barrier.

"The hope is that we can help patients live longer. We know that there are several drugs out there that should work on brain tumors," Tran said.