Table 2.
Univariate analysis of variables per patient
| Factors | Variables | n | Event | 5 y % | P value |
| Age (years) | ≤70 | 58 | 2 | 6.1 | 0.43 |
| >70 | 53 | 4 | 4.8 | ||
| BMI (kg/m2) | ≤24 | 80 | 4 | 5.5 | 0.86 |
| >24 | 31 | 2 | 5.3 | ||
| Tobacco (pack years) | ≤20 | 34 | 0 | 0 | 0.08 |
| >20 | 77 | 6 | 7.9 | ||
| Primary | Larynx | 92 | 4 | 4.5 | 0.06 |
| Hypopharynx | 19 | 2 | 16.7 | ||
| Hypertension | No | 59 | 2 | 4.2 | 0.25 |
| Yes | 52 | 4 | 7.2 | ||
| Dyslipidemia | No | 74 | 0 | 0 | <0.01 |
| Yes | 37 | 6 | 15.8 | ||
| Diabetes mellitus | No | 82 | 1 | 2 | 0.03 |
| Yes | 29 | 5 | 14.3 | ||
| Cardiovascular disease | No | 88 | 4 | 5.1 | 0.59 |
| Yes | 23 | 2 | 6.2 | ||
| Antiplatelet therapy | No | 89 | 5 | 5.1 | 0.71 |
| Yes | 22 | 1 | 6.2 | ||
| Dose per fraction (Gy) | ≤2 | 62 | 2 | 3.7 | 0.65 |
| >2 | 49 | 4 | 7.1 | ||
| Radiation field | WN | 29 | 2 | 5.1 | 0.44 |
| Box | 82 | 4 | 7.7 | ||
| Chemotherapy | No | 63 | 4 | 6.5 | 0.81 |
| Yes | 48 | 2 | 9.1 |
BMI: body mass index
WN: whole neck field including subclinical lymph node
Box; parallel-opposed fields with individualized wedge-filtered technique, 5 × 5 or 6 × 6 cm; Bold value indicates a significance level pf p < 0.05.