Laser technology was FDA-approved for surgical treatment of brain tumors in 2009. Now, new research demonstrates the ability of 1064 nm laser light to disrupt the blood-brain barrier, which protects the brain from toxins and has limited treatment options for brain cancer patients.1
In a pilot study of minimally invasive laser surgery for glioblastoma (the most common and aggressive type of brain cancer), researchers at Washington University School of Medicine in St. Louis (MO) unexpectedly found that MRI-guided laser interstitial thermal therapy (LITT) enabled permeability of the blood-brain barrier for up to six weeks—long enough for patients to receive multiple chemotherapy treatments. Because the opening in the protective layer can be confined to a spot near the tumor, the blood-brain barrier remains intact elsewhere—potentially limiting harmful effects of chemotherapy to other areas of the brain, the researchers said.
As part of the trial, 13 patients received doxorubicin intravenously in the weeks following surgery with the NeuroBlate laser ablation system (Monteris Medical). The researchers are closely following the participants, said Professor of Neurosurgery Eric C. Leuthardt, MD. "Our early results indicate that the patients are doing much better on average, in terms of survival and clinical outcomes, than what we would expect. We are encouraged but very cautious because additional patients need to be evaluated before we can draw firm conclusions."
Other successful attempts to breach the barrier have left it open for only about 24 hours (not long enough for consistent chemotherapy) or have produced limited benefit. The new findings may enable the application of other treatments, such as cancer immunotherapy, which harnesses cells of the immune system to locate and destroy cancerous tissue.
The pilot study is part of a phase II clinical trial that will involve 40 patients. The researchers are also planning another clinical trial combining the laser technology with chemotherapy and immunotherapy, as well as trials to test targeted cancer drugs that normally can't breach the blood-brain barrier.
1. E. C. Leuthardt et al., PLoS One, 11, 2, e0148613 (2016).