Table 2.

Imaging-guided localization

Variable	No. (%)
Imaging-guided localization of the clipped node: attempted
Yes	422 (84.4%)
No	78 (15.6%)

	N = 422
Imaging-guided localization of the clipped node: successful
Yes	413 (97.9%)
Unsure	5 (1.2%)
No	4 (0.9%)
Reason for failure (N = 4)
Clip not visible	3 (75.0%)
Wire missed target	1 (25.0%)
Type of clip used to mark the positive node (N = 500)
Direct magseed	36 (7.2%)
Direct radioactive seed	3 (0.6%)
Nitinol ring marker (nickel titanium alloy)	106 (21.2%)
Titanium or stainless-steel marker with gel	129 (25.8%)
Titanium or stainless-steel marker without gel	202 (40.4%)
Other	24 (4.8%)

	N = 307
Localization performed before surgery
Imaging modality used to localize the clipped node (before surgery)
Ultrasound	301 (98.0%)
Computed tomography	3 (1.0%)
Other	3 (1.0%)
Type of localization used (before surgery)
Magseed	5 (1.6%)
ROLL	91 (29.7%)
Radioactive seed	31 (10.1%)
Tattoo	6 (2.0%)
Wire	162 (52.9%)
Other	12 (3.9%)

	N = 115
Localization performed during surgery
Type of localization used (during surgery)
Tattoo	2 (1.7%)
Wire	65 (56.5%)
Ultrasound alone	30 (26.1%)
Other	18 (15.7%)

ROLL radioguided occult lesion localization