My project aims to accurately calculate the cumulative radiation damage sustained by patients who have received proton therapy in the vicinity of the lung. This can be accomplished by applying 3D deformable registration to time elapsed CT scans of patients throughout the breathing cycle. Image registration allows us to quantify tissue movement and understand the radiation dose received at each voxel at each time point of the breathing cycle. Analysis of this data will reveal how much tissue receives a lethal dose of radiation over the course of a proton therapy treatment. Discrepancies between physician estimates and my data might necessitate alternative treatment plants for patients who are more sensitive to radiation.