Lung cancer poses a unique problem. Delivery of precise, highly targeted radiation to the lung is difficult because the tumor moves as the patient’s lungs move during the process of breathing. If radiation is delivered to the lung without precise motion planning, the potential exists not only to miss the tumor, but also to damage healthy cells surrounding the tumor. The Phantom Lung is a device being developed by Hualiang Zhong, Ph.D., as part of a project funded by the National Institutes of Health. Teamour Nurushev, Ph.D., Indrin Chetty, Ph.D., as well as Gregory Auner, Ph.D. and his team of engineers assisted in the design and development of the Phantom Lung. This lung device allows radiation oncologists and medical physicists to work together to understand the nature of lung tumor motion and, consequently, to validate models developed to account for accurate targeting of the tumor during motion. Ultimately, the Phantom Lung will be used to improve patient outcomes by potentially improving targeting accuracy and limiting radiation dose to surrounding healthy cells.