Registration uncertainties between 3D cone beam computed tomography and different reference CT datasets in lung stereotactic body radiation therapy

Table 4 Spearman’s correlation coefficient Rs

Tumor characteristics	Automatic		Manual		Automatic vs manual
Tumor characteristics	CTs	R_s	CTs	R_s	CTs	R_s
Tumor motion	MIPvsPCT	0.482
	MidVvsPCT	0.353			∆PCT	0.635*
	AIPvsMIP	0.733*	MIPvsPCT	0.288	∆AIP	0.430
	AIPvsMidV	0.429	MIPvsMidV	0.488	∆MidV	0.568*
	MIPvsMidV	0.686*
Tumor volume	AIPvsMidV	−0.310	MIPvsPCT	0.324	–	–
SI distance	MIPvsPCT	0.286	^_	–	∆MidV	0.286
	AIPvsMIP	0.505*
	MIPvsMidV	0.355
Tumor environment	AIPvsMidV	−0.338	MIPvsPCT	0.294	–	–

Spearman’s correlation coefficient Rs between tumor characteristics and the 3D shift vector. Presented are registrations reaching significant correlations (p < 0.05)
PCT slow planning CT, AIP average intensity projection; MIP maximum intensity projection; MidV mid-ventilation
*indicates statistically significant differences with p < 0.01

ISSN: 1748-717X