Table 3.

(a) DIR evaluation metrics of the 6 structures in the POPI model for 4 tested systems. (b) Interuser variations reported for the same structure by Yang et al.¹⁹ Bolded text in (a) indicate values that are inferior to the reported interuser variation baseline

(a)	DSC				HD (mm)				HD95 (mm)				MDA (mm)
	MIM	Velocity	RS	Mirada	MIM	Velocity	RS	Mirada	MIM	Velocity	RS	Mirada	MIM	Velocity	RS	Mirada
Esophagus	0.75	0.71	0.73	0.77	15.7	17.5	15.9	13.9	5.2	6.2	7.4	5.4	1.6	2.0	1.9	1.6
Left ventricle	0.91	0.90	0.89	0.92	21.0	22.7	23.1	20.4	9.9	10.5	10.3	9.9	2.6	2.8	3.3	2.5
Leftt lung	0.98	0.96	0.98	0.98	29.4	22.4	29.6	20.0	4.2	5.3	5.9	2.4	0.9	1.3	1.0	0.6
Right lung	0.97	0.95	0.98	0.98	33.5	44.0	40.0	28.8	7.4	13.8	6.6	3.9	1.5	2.7	1.4	1.0
Spinal cord	0.94	0.89	0.94	0.94	3.9	4.9	3.9	3.7	1.7	2.1	1.7	1.4	0.5	0.9	0.6	0.5
Trachea	0.92	0.87	0.91	0.92	5.3	7.1	5.0	4.4	2.3	3.5	2.1	2.0	0.8	1.1	0.7	0.7
(b)					DSC					HD95 (mm)					MDA
Esophagus					0.82 ± 0.04					3.33 ± 0.90					1.07 ± 0.25
Heart					0.93 ± 0.02					6.42 ± 1.82					2.21 ± 0.59
Left lung					0.96 ± 0.02					5.17 ± 2.73					1.51 ± 0.67
Right lung					0.96 ± 0.02					6.71 ± 3.91					1.87 ± 0.87
Spinal cord (thoracic)					0.86 ± 0.04					2.38 ± 0.39					0.88 ± 0.23

Abbreviations: DIR = deformable image registration; DSC = Dice similarity coefficient; HD = Hausdorff distance.