Brain metastases occur in nearly one in three patients with lung cancer, and current treatments, such as surgery and radiation, offer limited options because many drugs cannot cross the blood-brain barrier, the brain’s natural defense system.

“Brain metastases are incredibly difficult to treat because most therapies simply can’t get inside the brain,” said Shih‑Ying Wu, Ph.D., assistant professor of radiation oncology at Wake Forest University School of Medicine and corresponding author.

“Macrophages, however, naturally know how to cross into the brain. So, we asked: ‘What if we could give them the ability to recognize and destroy cancer cells once they get there?'”