Table 2.

Detection rates per patient in delayed SLND

Detection rate (%)
	SPIO	Tc99	Difference	95% CI	p
WLE	100.0	100.0	0.0	− 9.1, 9,1	1.000
OPBCT	100.0	33.3	66.7	43.6, 89.7	< 0.001
Mastectomy	80.0	45.0	35.0	−18.3, 71.8	0.092
Total	92.7	50.9	41.8	24.3, 59.3	< 0.001

	SPIO+BD	Tc99+BD	Difference	95% CI	P
WLE	100.0	100.0	0.0	− 9.1, 9,1	1.000
OPBCT	100.0	58.3	41.7	17.8, 65.6	0.002
Mastectomy	95.0	50.0	45.0	14.2, 75.8	0.012
Total	98.2	63.6	34.5	19.2, 49.9	< 0.001

BD blue dye, CI confidence interval, OPBCT oncoplastic breast-conserving therapy, SPIO superparamagnetic iron oxide nanoparticles, Tc⁹⁹ Technetium 99, WLE wide local excision

p value is two-sided and refers to McNemar’s test for paired proportions