Table 1.
Patient and tumor characteristics in breast cancer patients receiving intraparenchymal vs intradermal injection of radioisotope
| Total | Intraparenchymal injection group | Intradermal injection group | |
| Procedures | 434 | 107 | 327 |
| Mean age, in years (range) | 58.8 (28–92) | 58.4 (28–92) | 58.9 (29–92) |
| Tumor location | |||
| UOQ | 219 (50%) | 62 (58%) | 157 (48%) |
| LOQ | 78 (18%) | 9 (8%) | 69 (21%) |
| UIQ | 53 (12%) | 10 (9%) | 43 (13%) |
| LIQ | 78 (18%) | 24 (22%) | 54 (17%) |
| Central | 6 (1%) | 2 (2%) | 4 (1%) |
| Tumor histology | |||
| Invasive ductal | 330 (76%) | 93 (87%) | 237 (72%) |
| Invasive lobular | 50 (12%) | 7 (7%) | 43 (13%) |
| DCIS | 44 (10%) | 3 (3%) | 41 (13%) |
| Other | 10 (2%) | 4 (4%) | 6 (2%) |
| Average tumor size, in cm (range) | 1.57 (0.1–6.5) | 1.35 (0.1–3.7) | 1.65 (0.1–6.5) |
| Stage | |||
| T0 (in situ) | 44 (10%) | 3 (3%) | 41 (13%) |
| T1a | 48 (11%) | 12 (11%) | 36 (11%) |
| T1b | 97 (22%) | 33 (31%) | 64 (20%) |
| T1c | 146 (34%) | 42 (39%) | 104 (32%) |
| T2 | 92 (21%) | 17 (16%) | 75 (23%) |
| T3 | 7 (2%) | 0 | 7 (2%) |
UOQ indicates upper outer quadrant; LOQ, lower outer quadrant; UIQ, upper inner quadrant; LIQ, lower inner quadrant; DCIS, ductal carcinoma in situ.