Table 3.

Head motion of five claustrophobic patients monitored with AlignRT in real time during treatment, and with both AlignRT and orthogonal kV imaging in pre‐ and post‐treatment (P&P). The average motion of these patients is similar to that of the volunteers. The X‐ray P&P data fall between two sets of AlignRT P&P data (OSI‐1 and OSI‐2) using different reference images. Note: both OSI‐1 and OSI‐2 show P&P differences, quantifying head motion during treatment, although OSI‐1 is more reliable since it does not carry residual head rotation at setup

				Translation (mm)					Rotation (degree)
				RTD		P&P X‐ray			RTD		P&P
Patient	Sex	Age	fx/Fxa	Mean	St dev	OSI‐1b	OSI‐2c	kV	Mean	St dev	OSI‐1	OSI‐2
1	M	65	16/30	1.2	0.6	1.3	2.3	1.7	0.5	0.2	0.6	1.1
2	F	72	11/20	0.7	0.1	0.9	1.5	1.0	0.3	0.1	0.3	1.2
3	M	59	16/33	0.6	0.3	0.5	1.4	1.2	0.3	0.1	0.2	0.6
4	M	76	4/5	0.5	0.2	1.3	1.0	1.1	0.6	0.2	0.8	0.2
5	F	55	14/33	0.9	0.4	1.1	1.6	1.4	0.4	0.2	0.4	0.8
Average		65	12/24	0.8	0.3	1.0	1.6	1.4	0.4	0.2	0.5	0.8
St dev				0.3		0.4	0.5	0.5	0.2		0.3	0.4

^afx/Fx refers to the number of fractions (fx) for which AlignRT was applied for motion monitoring over the total number of treatment fractions (Fx).

^bOSI‐1 uses the on‐site AlignRT image as the registration reference image, for pre‐ and post‐treatment registration.

^cOSI‐2 uses the CT external contours as the registration reference image, for pre‐ and post‐treatment registration.