RA DIAT I O N O N C O LO G Y Groundbreaking MRI-Guided Radiotherapy Opens Window to See Cancerous Tumors in Real Time As home to the first MRI-guided radiotherapy system in the western United States — and one of only three locations in the world — UCLA physicians in the Department of Radiation Oncology have an unparalleled ability to see and accurately target cancerous tumors, while making immediate adjustments to treatment delivery. This technological advance addresses a longstanding challenge for radiation oncologists, enabling them to see the targeted tumor and the surrounding healthy tissue during treatment and to ensure that the radiation beam stays within desired margins as tumors or organs move. Known as ViewRay, the technology combines continuous magnetic resonance imaging Images courtesy of ViewRay Incorporated UCLAHEALTH.ORG 1-800-UCLA-MD1 (1-800-825-2631) (MRI) with radiation therapy for cancer patients. It was approved by the U.S. Food and Drug Administration in 2012 for clinical use. “The ability to image in real time with high-quality MRI during therapy is new and a game-changer in all aspects,” says radiation oncologist Percy Lee, MD. MRI is the preferred method for imaging soft tissue because it can produce a clearer, more detailed view of internal organs than computed tomography (CT) without the radiation exposure associated with CT. In areas of the body such as the abdomen, pelvis and breast, MRI allows physicians to more easily differentiate a tumor from healthy tissue, and is especially useful for mobile tumors, which often change position