Figure 2.

Three-field intensity-modulated radiation therapy (IMRT) plan vs. two-field passive scatter proton therapy (PS-PT) plan for a posterior mediastinal stage IIIA non-small cell lung cancer treated with definitive chemoradiation therapy to 60 Gy in 2 Gy per fraction. Similar to Figure 1, PS-PT demonstrates reduced dose to the heart and lungs compared to IMRT, with decreased mean lung dose, lung volume receiving at least 5 Gy (V5), lung V20, and mean heart dose. Both plans depict the 20 Gy colorwash on lung windows on the average scan of the 4-dimensional computed tomography simulation. The red contour outlines the gross tumor volume.