Table 3.
Imaging parameters as predictors of PFS
| Variable | P-value | Hazard ratio | 95% CI |
|---|---|---|---|
| Mean positive pixel intensity prior to treatment | 0.61 | 1.01 | 0.98 – 1.04 |
| Mean positive pixel intensity following treatment | 0.72 | 1.00 | 0.99 – 1.02 |
| SD prior to treatment | 0.71 | 0.99 | 0.97 – 1.02 |
| SD following treatment | 0.33 | 0.99 | 0.97 – 1.01 |
| Entropy prior to treatment | 0.25 | 1.84 | 0.64 – 5.32 |
| Entropy following treatment | 0.08 | 2.23 | 0.91 – 5.49 |
| nSD prior to treatment | 0.01 | 0.01 | 0.000 – 0.31 |
| nSD following treatment | 0.003 | 0.01 | 0.001 – 0.22 |
| Kurtosis prior to treatment | 0.21 | 1.28 | 0.87 – 1.87 |
| Kurtosis following treatment | 0.34 | 1.12 | 0.89 – 1.41 |
| Skewness prior to treatment | 0.32 | 1.66 | 0.62 – 4.41 |
| Skewness following treatment | 0.65 | 1.20 | 0.55 – 2.61 |
| Percent change in size | 0.14 | 0.98 | 0.96 – 1.01 |
| Mean pixel intensity change | 0.36 | 0.99 | 0.98 – 1.01 |
| SD change | 0.51 | 0.70 | 0.25 – 2.02 |
| Entropy change | 0.21 | 15.12 | 0.21 – 1096.9 |
| nSD change | 0.06 | 0.02 | 0.00 – 1.21 |
| Kurtosis change | 0.92 | 1.06 | 0.37 – 3.04 |
| Skewness change | 0.81 | 0.94 | 0.56 – 1.58 |
Entries in bold were significant
Abbreviations: SD standard deviation, nSD size normalized standard deviation, PFS progression free survival