Table 1.

Mean structure contouring difficulty across the full 10 phases of a 4-dimensional computed tomography planning scan

Structure	Contouring difficulty
	Hodgkin lymphoma		Lung cancer
	Mean	Standard deviation	Mean	Standard deviation
Heart	1	0	1	0
Left atrium	1.1	0.29	1	0
Right atrium	1.1	0.29	1.2	0.42
Left ventricle	1.1	0.29	1.1	0.32
Right ventricle	1.1	0.29	1.2	0.42
Tricuspid valve	1.1	0.29	1.2	0.42
Mitral valve	1.1	0.29	1.1	0.32
Pulmonic valve	2.1	0.67	2.3	0.67
Aortic valve	2.3	0.65	3.1	0.88
Left anterior descending artery	1.6	0.67	2.3	0.95
Circumflex	2.3	0.49	3	1.15
Right coronary artery	2.8	0.97	3.2	0.92