Table 4 Univariate analysis
Radiation necrosis | ||
|---|---|---|
Parameters | Univariate analysis | |
HR (95% CI) | p-value | |
Gender (♂ vs. ♀) | 0.82 (0.20–3.29) | 0.780 |
Histology at first diagnosis (LGG vs. HGG) | 1.48 (0.35–6.22) | 0.590 |
Histology at second irradiation (LGG vs. HGG) | 0.28 (0.06–1.41) | 0.124 |
Malignant transformation (yes vs. no) | 5.51 (0.68–44.98) | 0.111 |
Treatment sequence (upfront SBT vs. upfront EBRT) | 4.44 (1.05–18.79) | 0.026* |
SBT | ||
Reference dose > 52 Gy | 2.11 (0.50–8.84) | 0.307 |
Dose rate > 12 cGy/h | 0.19 (0.02–1.53) | 0.119 |
Tumor volume > 6.3 ccm | 4.43 (1.04–18.90) | 0.028* |
Treatment time > 572 h | 17.05 (2.08–139.79) | < 0.001* |
Number of implanted seeds/patient | ||
> 2 seeds | 2.67 (1.22–5.76) | < 0.001* |
EBRT | ||
Treatment time > 43.5 days | 1.46 (0.36–5.84) | 0.595 |
Dose of single fraction > 1.8 Gy | 0.37 (0.09–1.47) | 0.156 |
Total dose > 60.0 Gy | 0.04 (0.00–3118.9) | 0.581 |
Cumulative BED after EBRT + SBT | ||
Total BED for late reacting tissue > 120 Gy3 | 0.13 (0.02–1.03) | 0.053 |
Total BED for tumor tissue > 87 Gy10 | 0.13 (0.02–1.03) | 0.053 |
Interval between EBRT and SBT | 0.99 (0.96–1.01) | 0.363 |
Sequential bevacizumab after re-irradiation—within 1 year (yes vs. no) | 0.04 (0.00–637.8) | 0.307 |