Table 3.
Univariable Cox proportional hazard analysis of relationship between continuous MRI variables and recurrence-free survival
| Recurrence-free survival | ||||
|---|---|---|---|---|
| MRI variable | Median | P value | Hazard ratio | 95 % CI |
| Baseline (before NAC) | ||||
| Largest diameter MIP/initial enhancement (90 s) | 43 mm | 0.238 | 1,009 | 0.994, 1.024 |
| Largest diameter plateau/washout enhancement (450 s) | 33 mm | 0.027 | 1,017 | 1.002, 1.033 |
| Initial enhancement (90 s) % | 152 % | 0.326 | 0.997 | 0.99, 1.003 |
| Late enhancement (450 s) % | −13 % | 0.947 | 0.999 | 0.967, 1.032 |
| During NAC | ||||
| Largest diameter MIP/initial enhancement (90s) | 30 mm | 0.155 | 1,011 | 0.996, 1.026 |
| Largest diameter plateau/washout enhancement (450 s) | 17 mm | 0.006 | 1,024 | 1.007, 1.041 |
| Initial enhancement % | 135 % | 0.993 | 1.00 | 0.995, 1.005 |
| Late enhancement % | −4 % | 0.600 | 0.995 | 0.975, 1.015 |
| After NAC | ||||
| Largest diameter MIP/initial enhancement (90s)a | 22 mm | 0.140 | 1.01 | 1.00, 1.03 |
| Largest diameter plateau/washout enhancement (450 s) | 0 mm | 0.003 | 1.03 | 1.01, 1.051 |
| Initial enhancement % | 100 % | 0.057 | 1,005 | 1.00, 1.011 |
| Late enhancement % | 9 % | 0.815 | 0.998 | 0.983, 1.014 |
| Percent change after NAC - baseline NAC % | ||||
| Largest diameter MIP/initial enhancement (90 s)b | −40 % | 0.280 | 1.01 | 0.99, 1.02 |
| Largest diameter plateau/washout enhancement (450 s)c | −100 % | 0.021 | 1,013 | 1.002, 1.024 |
| Percent change after NAC - during NAC % | ||||
| Largest diameter MIP/initial enhancement (90 s) mmb | −30 % | 0.290 | 1.01 | 0.99, 1.02 |
| Largest diameter plateau/washout enhancement (450 s)c | −61 % | 0.066 | 1,008 | 0.999, 1.017 |
aPatients with largest diameter 0 mm were excluded; bpatients with change −100 % were excluded; cpatients without washout/plateau on both scans were excluded. MRI magnetic resonance imaging, CI confidence interval, NAC neoadjuvant chemotherapy, MIP maximum intensity projection. Numbers in bold are significant