Patient Characteristics
| Patient no. | Age (y) | Histology | Stage | HER2 expression (FISH score) | Interval from CNB to 64Cu (mo) | Primary or metastatic size (cm) or location | No. of lesions visualized by MR imaging/CT/64Cu | History of trastuzumab treatment | Days from trastuzumab treatment to imaging |
| 1 | 73 | IDC-st | IV | 3+ | 20 | M, brain | 6/4/4 | Weekly | 1 d |
| 2 | 42 | IDC-SC | IIB | 3+ | 11 | P, 2.3 × 2.1 | NA/1/1 | Triweekly | 20 d |
| 3 | 49 | Lobular | IIA | 2+ (3.9) | 3 | P, 2.0 × 2.0 | NA/1/1 | — | — |
| 4 | 75 | IDC-SC | IV | 3+ | 10 | M, brain | 1/0/1 | Weekly | 1 d |
| 5 | 55 | IDC-st | IIA | 3+ | 22 | P, 3.5 × 3.5 | NA/1/1 | Triweekly | 8 d |
| 6 | 45 | IDC-SC | IV | 3+ | 1 | M, hilar node | NA/1/1 | — | — |
CNB = core-needle biopsy; 64Cu = 64Cu-DOTA-trastuzumab PET; IDC-st = invasive ductal carcinoma–solid tubular; IDC-SC= invasive ductal carcinoma–scirrhous; M = metastatic breast cancer; P = primary breast cancer; NA = not applied within 1 mo before or after 64Cu-DOTA-trastuzumab PET imaging; weekly = 2 mg/kg/wk; triweekly = 8 mg/kg/3 wk.