PTV Margins
The median translational set up errors in X (lateral), Y (cephalo-caudal), and Z (ventral-dorsal) directions were 0.01 ± 0.14 cm, 0.02 ± 0.20 cm, and 0.06 ± 0.20 cm, respectively. The corresponding PTV margins were calculated as 0.49 cm, 0.69 cm, and 0.65 cm, respectively.