Table 2.
Univariate analysis of overall survival and local control.
| Clinical Factor | Chordoma (n = 32) | Clinical Factor | Non-Chordoma (n = 21) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| n | 3-y OS (%) | p | 3-y LC (%) | p | n | 3-y OS (%) | p | 3-y LC (%) | p | ||
| Age | Age | ||||||||||
| ≤67 | 16 | 100 | 0.059 | 100 | 0.611 | ≤54 | 11 | 87.5 | 0.056 | 81.8 | 0.638 |
| >67 | 16 | 83.9 | 84.8 | >54 | 10 | 33.8 | 85.7 | ||||
| Sex | Sex | ||||||||||
| Male | 24 | 93.8 | 0.816 | 100 | 0.061 | Male | 8 | 43.8 | 0.259 | 72.9 | 0.595 |
| Female | 8 | 83.3 | 71.4 | Female | 13 | 73.4 | 88.9 | ||||
| Chemotherapy | Chemotherapy | ||||||||||
| Presence | 0 | NA | NA | NA | NA | Presence | 14 | 61.1 | 0.785 | 90.9 | 0.131 |
| Absence | 32 | 91.3 | 92.5 | Absence | 7 | 60.0 | 66.7 | ||||
| Performance status | Performance status | ||||||||||
| 0–1 | 30 | 95.5 | 0.042 * | 92.0 | 0.649 | 0–1 | 17 | 56.8 | 0.510 | 83.9 | 0.992 |
| 2–3 | 2 | 50.0 | 100 | 2–3 | 4 | 75.0 | 75.0 | ||||
| Prior treatment | Prior treatment | ||||||||||
| Presence | 5 | 89.9 | 0.554 | 90.9 | 0.435 | Presence | 8 | 59.8 | 0.713 | 90.0 | 0.422 |
| Absence | 27 | 100 | 100 | Absence | 13 | 60.0 | 71.4 | ||||
| Distance of tumor-GI | Distance of tumor-GI | ||||||||||
| ≤3 mm | 18 | 85.6 | 0.574 | 86.9 | 0.134 | ≤3 mm | 14 | 20.8 | 0.070 | 75.0 | 0.849 |
| >3 mm | 14 | 100 | 100 | >3 mm | 7 | 76.6 | 84.6 | ||||
| Distance of tumor-GI | Distance of tumor-GI | ||||||||||
| ≤5 mm | 22 | 87.4 | 0.718 | 88.9 | 0.256 | ≤5 mm | 11 | 51.4 | 0.908 | 87.5 | 0.671 |
| >5 mm | 10 | 100 | 100 | >5 mm | 10 | 67.5 | 77.8 | ||||
| GTV volume, cm3 | GTV volume, cm3 | ||||||||||
| ≤300 | 21 | 100 | 0.067 | 100 | 0.014 * | ≤300 | 14 | 64.7 | 0.418 | 77.9 | 0.165 |
| >300 | 11 | 77.1 | 77.9 | >300 | 7 | 51.4 | 100 | ||||
| GTV D98, Gy (RBE) | GTV D98, Gy (RBE) | ||||||||||
| ≤64.0 | 14 | 77.1 | 0.269 | 92.3 | 0.969 | ≤69.0 | 11 | 60.0 | 0.58 | 88.9 | 0.674 |
| >64.0 | 18 | 100 | 93.3 | >69.0 | 10 | 60.0 | 77.8 | ||||
| GTV D95, Gy (RBE) | GTV D95, Gy (RBE) | ||||||||||
| ≤66.0 | 15 | 77.1 | 0.269 | 92.9 | 0.895 | ≤69.4 | 11 | 78.8 | 0.33 | 87.5 | 0.364 |
| >66.0 | 17 | 100 | 92.9 | >69.4 | 10 | 40.0 | 76.2 | ||||
| GTV V64, % | GTV V64, % | ||||||||||
| ≤98 | 13 | 74.1 | 0.216 | 91.7 | 0.867 | ≤98 | 1 | 100 | 0.821 | 100 | 0.520 |
| >98 | 19 | 100 | 93.8 | >98 | 20 | 58.2 | 81.1 | ||||
| GTV V60, % | GTV V60, % | ||||||||||
| ≤98 | 3 | 100 | 0.372 | 100 | 0.553 | ≤98 | 0 | NA | NA | NA | NA |
| >98 | 29 | 89.9 | 91.5 | >98 | 21 | 60.7 | 82.2 | ||||
| GTV V<64, cm3 | GTV V<65, cm3 | ||||||||||
| ≤1 | 12 | 100 | 0.508 | 100 | 0.13 | ≤1 cm3 | 16 | 63.3 | 0.324 | 79.4 | 0.854 |
| >1 | 20 | 84.4 | 86.6 | >1 cm3 | 5 | 50 | 100 | ||||
| GTV V<60, cm3 | GTV V<60, cm3 | ||||||||||
| ≤1 | 20 | 92.3 | 0.876 | 100 | 0.035 * | ≤1 | 18 | 66.1 | 0.26 | 81.1 | 0.42 |
| >1 | 12 | 90 | 81.5 | >1 | 3 | 33.3 | 100 | ||||
Abbreviations: D95 and D98, the minimum dose that covered 95% and 98% of the target volume; GTV, gross tumor volume; LC, local control; OS, overall survival; RBE, relative biological effectiveness; V60 and V64, percentage of the GTV volume that received at least 60 and 64 Gy (RBE); V<60 and V<64, the target volume that received less than 60 and 64 Gy (RBE). * p < 0.05.