Table 2.

kV/kV and OSMS image pair couch rotation–induced shifts (ie, difference between shift at angle and shift at 0)

	CR 45°	CR 315°	CR 30°	CR 330°	CR 15°	CR 345°
kV/kV Image Pairs
Vrt (mm)	0.25 (0.00-0.50)	0.14 (0.00-0.40)	0.29 (0.10-0.60)	0.25 (0.10-0.40)	0.24 (0.00-0.40)	0.24 (0.00-0.80)
Lng (mm)	0.30 (0.10-0.60)	0.21 (0.00-0.40)	0.17 (0.00-0.40)	0.23 (0.00-0.40)	0.17 (0.00-0.70)	0.21 (0.00-1.00)
Lat (mm)	0.49 (0.30-0.90)	0.71 (0.30-1.10)	0.31 (0.00-1.00)	0.22 (0.00-0.50)	0.12 (0.00-0.20)	0.63 (0.20-1.10)
Yaw (°)	0.16 (0.00-0.40)	0.50 (0.20-1.10)	0.13 (0.00-0.30)	0.19 (0.00-0.50)	0.17 (0.10-0.40)	0.26 (0.00-0.60)
Pitch (°)	0.54 (0.00-1.00)	0.11 (0.00-0.40)	0.39 (0.00-0.90)	0.34 (0.10-0.60)	0.32 (0.00-0.60)	0.22 (0.00-0.50)
Roll (°)	0.31 (0.00-0.70)	0.44 (0.00-1.00)	0.50 (0.20-0.80)	0.48 (0.10-1.00)	0.38 (0.10-1.10)	0.62 (0.00-1.40)
OSMS
Vrt (mm)	0.03 (0.10-0.50)	0.10 (0.00-0.10)	0.40 (0.10-0.70)	0.10 (0.10-0.20)	0.20 (0.00-0.30)	0.40 (0.10-0.70)
Lng (mm)	0.40 (0.10-0.60)	0.10 (0.00-0.30)	0.40 (0.30-0.40)	0.10 (0.00-0.30)	0.30 (0.00-0.60)	0.10 (0.00-0.10)
Lat (mm)	0.30 (0.10-0.60)	0.90 (0.70-1.10)	0.20 (0.10-0.30)	0.10 (0.10-0.20)	0.20 (0.20-0.20)	0.70 (0.50-0.80)
Yaw (°)	0.58 (0.40-0.80)	0.06 (0.00-0.10)	0.48 (0.30-0.60)	0.14 (0.00-0.40)	0.32 (0.20-0.40)	0.16 (0.00-0.40)
Pitch (°)	0.50 (0.40-0.60)	0.18 (0.10-0.30)	0.38 (0.30-0.50)	0.20 (0.10-0.40)	0.28 (0.20-0.40)	0.06 (0.00-0.10)
Roll (°)	0.24 (0.10-0.40)	0.24 (0.10-0.40)	0.36 (0.30-0.40)	0.10 (0.00-0.20)	0.08 (0.00-0.10)	0.28 (0.10-0.50)

CR, couch rotation; Lat, lateral; Lng, longitudinal; OSMS, Optical Surface Monitoring System; Vrt, vertical.