Table 4.

Spatial accuracy performance of the two algorithms CPP and 4DLTM.

Patient	Number of landmarks	Algorithm	Average spatial error of image registration
			3D-Euclidean	Right-left	Anterior-posterior	Superior-inferior
1	1280	CPP	1.07 (1.10)	0.32 (0.49)	0.34 (0.51)	0.61 (1.12)
		4DLTM	0.97 (1.02)	0.32 (0.49)	0.34 (0.50)	0.49 (1.01)
		p-value	1.36e-4
2	1487	CPP	0.99 (1.12)	0.35 (0.57)	0.36 (0.62)	0.49 (1.02)
		4DLTM	0.86 (1.08)	0.31 (0.55)	0.32 (0.60)	0.38 (0.95)
		p-value	5.91e-10
3	1561	CPP	1.23 (1.32)	0.38 (0.59)	0.40 (0.64)	0.73 (1.29)
		4DLTM	1.01 (1.17)	0.37 (0.58)	0.36 (0.61)	0.48 (1.09)
		p-value	0
4	1166	CPP	1.51 (1.58)	0.52 (0.74)	0.58 (0.80)	0.81 (1.52)
		4DLTM	1.40 (1.57)	0.52 (0.76)	0.54 (0.79)	0.70 (1.48)
		p-value	2.93e-5
5	1268	CPP	1.95 (2.02)	0.64 (0.92)	0.69 (0.88)	1.24 (1.96)
		4DLTM	1.67 (1.79)	0.58 (0.82)	0.69 (0.96)	0.92 (1.66)
		p-value	1.42e-13
6	419	CPP	1.94 (1.72)	0.60 (0.95)	0.59 (0.81)	1.35 (1.62)
		4DLTM	1.58 (1.65)	0.54 (0.93)	0.61 (0.88)	0.93 (1.44)
		p-value	2.30e-8
7	398	CPP	1.79 (1.46)	0.55 (0.64)	0.68 (0.87)	1.11 (1.49)
		4DLTM	1.46 (1.29)	0.47 (0.61)	0.58 (0.70)	0.82 (1.30)
		p-value	2.39e-6
8	476	CPP	1.96 (2.33)	0.64 (0.94)	0.71 (1.07)	1.25 (2.19)
		4DLTM	1.77 (2.12)	0.53 (0.82)	0.68 (0.92)	1.08 (2.05)
		p-value	2.43e-3
9	342	CPP	1.33 (1.17)	0.41 (0.56)	0.59 (0.70)	0.67 (1.17)
		4DLTM	1.19 (1.12)	0.41 (0.57)	0.51 (0.62)	0.57 (1.10)
		p-value	6.31e-3
10	435	CPP	1.84 (1.90)	0.48 (0.66)	0.71 (0.89)	1.21 (1.89)
		4DLTM	1.59 (1.87)	0.45 (0.66)	0.65 (0.96)	0.95 (1.77)
		p-value	1.86e-5
Avg		CPP	1.44 (1.54)	0.46 (0.70)	0.51 (0.75)	0.85 (1.49)
		4DLTM	1.25 (1.43)	0.43 (0.67)	0.48 (0.74)	0.65 (1.34)
		p-value	0.001953

Spatial errors presented in millimeters with standard deviation (SD) in parentheses. The Wilcoxon rank sum test was performed as described above, with corresponding p-values shown. Abbreviations: Avg=average, CPP=incremental 3D local compressible flow, 4DLTM= 4D local compressible flow.