Table 1.

List of imaging parameters investigated in this study. The centroid position of the volume of interest was defined in the peak-exhale phase of the first scan and determined how all generated 2D images were positioned.

Imaging parameter	Investigated settings	Description
Pixel size	2.0 mm–5.0 mm in 1.0 mm steps	Square pixels
Slice thickness	5.0 mm–10.0 mm in 2.5 mm steps
Imaging plane orientation	−80° to 90° in 10° steps	Rotation around the superior–inferior axis, rotation angle relative to the coronal plane
Acquisition strategy	Slice	A single plane intersecting with the centroid of the volume of interest
	Stack	Three parallel, adjacent imaging planes with the central one passing through the tumor or organ centroid
	Cross	Two orthogonal planes, intersecting at the tumor or organ centroid
Template generation strategy	2Dsingle	A single template per imaging plane is extracted from the peak-exhale phase of the first scan
	2Dmulti	10 templates are created from all respiratory phases of the first scan
	3Dsingle	2 additional templates (3 in total) are generated from adjacent imaging planes from the peak-exhale phase, potentially increasing robustness against through-plane motion
	3Dmulti	Similar to 3Dsingle, 20 additional templates (30 in total) are extracted from the adjacent slices at all 10 respiratory phases