Radiation therapy, a widely used treatment for brain metastases, can impair important brain functions like memory, processing speed, and attention span, often greatly affecting patients’ quality of life. Initial results from a large clinical trial now suggest that an advanced radiotherapy technique can limit the harm to patients’ cognitive function compared to standard radiation therapy without affecting the treatment’s ability to shrink or control brain tumors. In the NCI-funded trial, patients with brain metastases were treated with the drug memantine (Namenda), which has been shown to help protect cognitive function, and whole-brain radiation therapy (WBRT). Half of the patients, however, received a technically advanced form of WBRT that specifically avoided the hippocampus, an area in the lower-middle portion of the brain. Compared with patients who received standard WBRT, those who underwent hippocampal-avoidance WBRT were less likely to experience declines in cognitive function, said the trial’s co-lead investigator, Vinai Gondi, M.D., director of research at the Northwestern Medicine Proton Center and the Northwestern Medicine Cancer Center Warrenville. Dr. Gondi recently reported the trial’s findings at the annual meetings of the American Society for Radiation Oncology (ASTRO) and the Society for Neuro-Oncology (SNO). The results confirm earlier studies that had suggested the hippocampus is highly sensitive to radiation, he said. They also verify that, by sparing the hippocampus, “we can achieve the objectives of protecting patients’ cognitive function, effectively managing their brain metastases, and improving neurological symptoms.” Christina Tsien, M.D., of the Washington University School of Medicine in St. Louis, speaking at the ASTRO meeting, said that hippocampal-avoidance WBRT now represents a standard of care for patients with brain metastases. But, Dr. Tsien cautioned, “it’s a complex era” when it comes to treating cancer that has spread to the brain. With multiple approaches and therapies, she continued, treating brain metastases is now “much more nuanced” than it once was.