Patients with non-small cell lung cancer treated with preventative brain radiation (called prophylactic cranial irradiation or PCI), significantly decrease their risk of developing brain metastases (cancer spread in the brain) by more than 50 percent (from 18 percent to 8 percent), compared to those who did not receive the treatment, according to a randomized study presented at the plenary session November 2, 2009, at the 51st Annual Meeting of American Society for Radiation Oncology (ASTRO).