Laser Focus on Brain Cancer

“The blood–brain barrier (BBB) is a huge problem in brain cancer treatment. Although it’s a critical protective barrier, it also blocks out most chemo drugs from effectively treating brain tumors,” says David Tran, Chief of Neuro-Oncology in the Department of Neurosurgery, at the University of Florida School of Medicine. He continues, “If the BBB in the peritumoral region could be disrupted, then the delivery of cytotoxic chemotherapy in that area could be improved.” Which was exactly what Tran aimed to do when he co-led a new study with colleagues at Washington University in St. Louis (1).

The research team used a hyperthermic laser to destroy recurrent glioblastomas, and found that the heat treatment disrupted the BBB in the peritumoral region, where 90 percent of recurrent tumors occur. Their data showed that laser-induced hyperthermia caused disruption of the BBB for 4–6 weeks, with peak permeability occurring within 1–2 weeks.

Laser ablation may have the added benefit of helping the body generate an immune response to the tumor, says Tran, “The entire heat-killed tumor remains in situ and the disrupted BBB allows the release of inactivated tumor proteins into the bloodstream, generating an anti-tumor immune reaction that has the potential to improve survival.”

“This is the first time that anyone has definitively disrupted the peritumoral BBB long enough to present a unique window to deliver chemotherapy that would otherwise be unable to get through because of the BBB,” Tran continues. The team will now focus on exploiting this breach of the brain’s defenses. “We’re developing new studies that combine this technology with several targeted therapies and immunotherapies.”