Figure 3

Fusion of CT images and %dose-depth curve. a. CT image at the radiation treatment planning and %dose-depth curve. % Dose decreased sharply at the tangential line. b. CT imaging at the diagnosis of OP and %dose-depth curve. The line (A) shows the border between RP and FRS. The intersection (arrow) of the line with the %depth-dose curve is associated with a radiation dose > 20 Gy. The RP lesion might appear closer to the chest wall because of lung volume reduction related to fibrotic change following RP. c. The 20 Gy point of the %dose-depth curve moved to the border of RP. The FRS corresponds with the region of steep change of distribution.