Table 1.
Patient and imaging characteristics
| Wire (n = 332; 334 breasts, 340 lesions) | Seed (n = 327; 330 breasts, 333 lesions) | Total (n = 659; 664 breasts, 673 lesions) | |
|---|---|---|---|
| Age (years)* | 60.7(10.4) | 60.3(10.2) | 60.5(10.3) |
| Radiological lesion size (mm)*† | 13.2(8.9) | 13.2(8.9) | 13.2(8.9) |
| Sentinel node biopsy performed | |||
| Yes | 245 (73.4) | 244 (73.9) | 489 (73.6) |
| No | 89 (26.6) | 86 (26.1) | 175 (26.4) |
| Neoadjuvant therapy | |||
| Yes | 8 (2.4) | 11 (3.4) | 19 (2.9) |
| No | 324 (97.6) | 316 (96.6) | 640 (97.1) |
| Mammogram findings | |||
| Clip only | 4 (1.2) | 5 (1.5) | 9 (1.3) |
| Calcification | 90 (26.5) | 100 (30.0) | 190 (28.2) |
| Distortion | 18 (5.3) | 18 (5.4) | 36 (5.3) |
| Localized increased density | 31 (9.1) | 38 (11.4) | 69 (10.3) |
| Mass | 151 (44.4) | 138 (41.4) | 289 (42.9) |
| Mass and calcification | 14 (4.1) | 13 (3.9) | 27 (4.0) |
| Visible, not specified | 5 (1.5) | 7 (2.1) | 12 (1.8) |
| Not visible | 27 (7.9) | 14 (4.2) | 41 (6.1) |
| Ultrasound findings | |||
| Visible | 248 (72.9) | 245 (73.6) | 493 (73.3) |
| Not visible | 52 (15.3) | 46 (13.8) | 98 (14.6) |
| Not done | 40 (11.8) | 42 (12.6) | 82 (12.2) |
| Preoperative MRI | |||
| Yes | 25 (7.4) | 33 (9.9) | 58 (8.6) |
| No | 315 (92.6) | 300 (90.1) | 615 (91.4) |
| Guidance method for localization | |||
| Mammography | 113 (33.2) | 114 (34.2) | 227 (33.7) |
| Ultrasonography | 226 (66.5) | 215 (64.6) | 441 (65.5) |
| Not specified | 1 (0.3) | 4 (1.2) | 5 (0.7) |
| Lesions where bracketing used | |||
| Yes | 26 (7.6) | 22 (6.6) | 48 (7.1) |
| No | 314 (92.4) | 311 (93.4) | 625 (92.9) |
Values in parentheses are percentages unless indicated otherwise; *values are mean(s.d.). †Radiological size not recorded for eight breasts (hookwire, 2; seed, 6); size derived from largest measurement on mammography or ultrasonography, and tumour size summed for eight breasts with multifocal tumours.