Patient Characteristics
| Characteristic | Same site/scanner (n = 10) | Same institution, different scanner (n = 2) | Different site/scanner (n = 11) | All patients (n = 23) |
| Age (y) | 53.5 (32–67) | 58 (45–71) | 66 (43–76) | 60 (32–76) |
| Body mass index at scan 1 (kg/m2) | 28.3 (18.3–37.6) | 38.6 (31.4–45.7) | 28.4 (22.5–43.2) | 28.4 (18.3–45.7) |
| Time between scans (d) | 8 (2–15) | 7 (1–13) | 10 (7–14) | 9 (1–15) |
| Lesions* (n) | 5 (1–9) | 17 (9–25) | 5 (1–17) | 5 (1–25) |
| Sex (n) | ||||
| Male | – | – | 3 | 3 (13%) |
| Female | 10 | 2 | 8 | 20 (87%) |
| Diagnosis (n) | ||||
| Breast cancer | 10 | 2 | 6 | 18 (78%) |
| Other† | – | – | 5 | 5 (22%) |
| Ongoing treatment between scans (n) | ||||
| None | 2 | – | 5 | 7 (30%) |
| Bisphosphonates or biologic only | 1 | 1 | 1 | 3 (13%) |
| Endocrine therapy‡ | 4 | – | 3 | 7 (30%) |
| Chemotherapy§ | 3 | 1 | 2 | 6 (26%) |
| PET/CT scanner (n) | ||||
| Discovery STE (both) | 10 | 2 | – | 12 (52%) |
| Ingenuity TF | – | – | 6 | 6 (26%) |
| Biograph 6 | – | – | 3 | 3 (13%) |
| Biograph 20 mCT | – | – | 2 | 2 (9%) |
↵* All identified, but ≤25 lesions/patient used in analysis.
↵† 1 each: colorectal, head/neck, stage IV lung, stage III melanoma, neuroendocrine/Merkel cell cancer.
↵‡ 2 also bisphosphonates; 3 also biologic.
↵§ 4 also biologic; 1 also endocrine. Biologics: erlotinib, trastuzumab, everolimus, pertuzumab, denosumab, ado-trastuzumab emtansine. Cytotoxic agents: capecitabine, cyclophosphamide, doxorubicin.
Continuous data are expressed as median and range.