Table 4.
Unadjusted Explanatory Variable Characteristics by Treatment Technique
| Variable (n = patients) | Type | Median | Min | Max | IQR | Overall P value | Pairwise P value |
|---|---|---|---|---|---|---|---|
| Median age (years) (n = 3302) |
Conventional | 50.0 | 34 | 57.6 | 6.9 | .06 | .18 vs SRS <.01 vs FSRT |
| SRS | 49.9 | 45 | 64.0 | 5.0 | <.01 vs FSRT | ||
| FSRT | 53.9 | 37 | 62.0 | 2.1 | - | ||
| Median interval (months) (n = 2494) | Conventional | 19.1 | 10 | 39.4 | 7.4 | <.0001 | <.01 vs SRS <.01 vs FSRT |
| SRS | 11 | 5.8 | 16.8 | 2.5 | <.01 vs FSRT | ||
| FSRT | 10.6 | 3.1 | 29.0 | 6.0 | |||
| Cumulative EQD2 (Gy) (n = 2827) | Conventional | 96 | 80 | 114 | 0 | <.0001 | <.01 vs SRS <.01 vs FSRT |
| SRS | 123.8 | 102 | 167 | 14.3 | <.01 vs FSRT | ||
| FSRT | 108.1 | 86.1 | 103.8 | 4.4 | - | ||
| Re-irradiation EQD2 (Gy) (n = 3205) |
Conventional | 36 | 20 | 54 | 0 | <.0001 | <.01 vs SRS <.01 vs FSRT |
| SRS | 63.8 | 42 | 110 | 16.5 | <.01 vs FSRT | ||
| FSRT | 48.1 | 26.1 | 64.4 | 4.4 | - | ||
| Dose per fraction (Gy) (n = 3205) | Conventional | 2.0 | 1.3 | 2 | 0 | <.0001 | <.01 vs SRS <.01 vs FSRT |
| SRS | 15.0 | 7.7 | 20 | 3 | <.01 vs FSRT | ||
| FSRT | 5 | 2.5 | 6.3 | 2.5 | |||
| Median PTV (ml) (n = 1961) |
Conventional | 105.8 | 46.5 | 424 | 61.1 | <.0001 | <.01 vs SRS <.01 vs FSRT |
| SRS | 10.1 | 1.22 | 30 | 4.3 | <.01 vs FSRT | ||
| FSRT | 35 | 2.7 | 55.1 | 9.9 | - |
Abbreviations: IQR, interquartile range; SRS, stereotactic radiosurgery; FSRT, fractionated stereotactic radiotherapy; EQD2, equivalent dose in 2Gy per fraction; PTV, planning target volume.