Table 2.

The speck width and the voxel intensity of 0.40 mm top speck for six isocenter horizontal-shifts

Isocenter shift	0 shift	2pixel shift	4pixel shift	6pixel shift	8pixel shift	10pixel shift
Uncalibrated width	2 pixels	2 pixels	2 pixels	3 pixels	3 pixels	4 pixels
Calibrated width	2 pixels	2 pixels	2 pixels	2 pixels	2 pixels	2 pixels
Uncalibrated intensity	0.49	0.42	0.37	0.35	0.31	0.27
Calibrated intensity	0.51	0.49	0.47	0.45	0.43	0.41