Table 2.

Summary of intra-user and inter-user studies performed using both phantoms in three different configurations. Due to the experimental setup, the expected mean offset was 5.00 mm in each case. For the difference in the superior direction, the data from both coronal and sagittal films was averaged. Note that the difference between the mean offsets as measured by both phantoms in all scenarios considered never exceeded 0.15 mm.

				Anterior of Film Center		Superior of Film Center		Left of Film Center
Phantom	Framed/ Frameless	IGRT Type	Type of Investigation	Mean Offset (mm)	Std Dev (mm)	Mean Offset (mm)	Std Dev (mm)	Mean Offset (mm)	Std Dev (mm)
Lucy	Framed	None	Interuser	4.53	0.25	4.48	0.22	5.36	0.26
StereoPHAN	Framed	None	Interuser	4.59	0.11	4.49	0.19	5.50	0.25
Lucy	Framed	None	Intrauser	4.51	0.12	4.61	0.11	5.19	0.12
StereoPHAN	Framed	None	Intrauser	4.49	0.11	4.53	0.10	5.12	0.08
Lucy	Frameless	ExacTrac	Interuser	4.55	0.11	4.52	0.13	4.66	0.13
StereoPHAN	Frameless	ExacTrac	Interuser	4.44	0.12	4.45	0.15	4.65	0.10
Lucy	Frameless	ExacTrac	Intrauser	4.52	0.13	4.57	0.15	4.72	0.12
StereoPHAN	Frameless	ExacTrac	Intrauser	4.49	0.12	4.52	0.15	4.72	0.11
Lucy	Frameless	kV CBCT	Interuser	4.47	0.15	4.69	0.13	4.78	0.12
StereoPHAN	Frameless	kV CBCT	Interuser	4.46	0.12	4.61	0.13	4.81	0.14
Lucy	Frameless	kV CBCT	Intrauser	4.45	0.15	4.66	0.10	4.85	0.12
StereoPHAN	Frameless	kV CBCT	Intrauser	4.42	0.11	4.59	0.12	4.82	0.11