Phantom investigation of 3D motion-dependent volume aliasing during CT simulation for radiation therapy planning

Radiation Oncology

Table 4 Ratio of dGTVs and corresponding tGTVs.

Target Diameter (mm)	S-I Motion Amplitude ± (mm)	Single-slice Fast			Multi-slice Fast			Single-slice Slow
		Min	Mean	Max	Min	Mean	Max	Min	Mean	Max
10	5	0.21	0.54	0.81	0.36	0.61	0.80	0.83	0.98	1.20
	10	0.50	0.57	0.62	0.66	0.77	0.90	1.22	1.46	1.80
	15	0.51	0.76	1.07	0.88	0.99	1.11	2.17	2.38	2.50
31.5	5	0.57	0.63	0.67	0.72	0.73	0.76	0.71	0.75	0.78
	10	0.65	0.68	0.70	0.80	0.84	0.88	0.83	0.88	0.93
	15	0.70	0.73	0.77	0.94	0.98	1.01	0.98	1.06	1.13

Ratio gauges the proximity of the magnitude of a reconstructed dGTV with that of its corresponding time-averaged motion profile (tGTV). Each target motion in the S-I direction was synchronized with a fixed rotational motion resulting in an R-L and an A-P displacement of ± 2 and ± 5 mm, respectively.

ISSN: 1748-717X