Figure 4: Top: relation between range of motion and a spherical volume corresponding to the simulated PTVs for three dose levels – 60 Gy, 70 Gy, and 80 Gy. The nominal lung volume is 5029 cm3. Bottom: relation between range of motion and a spherical volume corresponding to simulated PTV with different radii. Nominal lung volume for this case is 6000 cm3.