Table 4.

Differences of DVH parameters: Comparison of the distributions of DVH parameter resulting from three different IGRT correction strategies (each fraction of all patients contributes equally)

	RIR_box_large: Δ to plan[%]	RIR_box_small: Δ[%]	DIR_fit: Δ[%]	p-value
	[−max, 25%, 50%, 75% + max]	[−max, 25%, 50%, 75%, + max]	[−max, 25%, 50%, 75%, + max]
SC D2	[−3.2, −0.6, 0.5, 1.7, 5.4]	[−4.6, −0.5, 0.7, 1.7, 5.8]	[−4.1, −0.7, 0.3, 1.5, 4.1]	0.29
tCTV D95	[−7.3, 0.0, 0.5, 1.1, 2.7]	[−7.1, −0.2, 0.5, 1.1, 2.9]	[−7.3, −0.3, 0.3, 0.9, 2.1]	<0.01
pCTV D95	[−3.3, 0.0, 0.6, 1.2, 2.7]	[−3.5, −0.6, 0.3, 1.0, 3.0]	[−3.6, −0.4, 0.6, 1.3, 2.9]	0.01

Abbreviations: SC = spinal cord; tCTV = therapeutic CTV; pCTV = prophylactic CTV; RIR = rigid image registration; DIR = deformable image registration; Δ = deviation from the planned corresponding value.

Distribution scheme: [max negative deviation; lower quartile^(25%); median^(50%); upper quartile^(75%); max positive deviation].