Table I.
Patient characteristics.
| Characteristic | RP group | No RP group | P-value |
|---|---|---|---|
| Patients, n | 8 | 32 | 0.043 |
| Age, years | 63 | 61 | 2.546 |
| Gender, n | |||
| Male | 5 | 22 | 0.046 |
| Female | 3 | 10 | 0.032 |
| Smoking history, n | |||
| ≤20 years | 3 | 13 | 0.054 |
| ≥20 years | 6 | 18 | 0.032 |
| Tumor location, n | |||
| Upper | 3 | 11 | 0.210 |
| Middle | 2 | 8 | 0.036 |
| Lower | 3 | 13 | 0.041 |
| GTV, cm3 | 156 | 148 | 6.354 |
| Mean lung volume, cm3 | 3218 | 3276 | 9.012 |
| Pathological type, n | |||
| Squamous carcinoma | 3 | 13 | 0.037 |
| Adenocarcinoma | 5 | 19 | 0.026 |
| Tumor stage, n | |||
| I–II | 3 | 15 | 0.025 |
| III–VI | 5 | 17 | 0.031 |
| V20, n | |||
| ≤25% | 1 | 6 | 0.044 |
| 25% <V20 <35% | 2 | 17 | 0.015 |
| ≥35% | 5 | 9 | 0.086 |
| MLD, n | |||
| ≤15 Gy | 3 | 18 | 0.047 |
| >15 Gy | 6 | 14 | 0.562 |
| Time to development of RP, days | |||
| Mean | 82.4 | 78.4 | 0.947 |
| Range | 78–86 | 60–83 | 0.032 |
| Interval between PET and | |||
| radiotherapy, days | |||
| Mean | 42 | 44 | 6.451 |
| Range | 28–56 | 28–60 | 1.011 |
| Radiation dose, Gy | |||
| Mean | 65.6 | 62.8 | 7.518 |
| Range | 60–72 | 60–72 | 6.312 |
| Chemotherapy, n | |||
| Single agent | 0 | 2 | 5.138 |
| Combined | 8 | 30 | 0.087 |
RP, radiation pneumonitis; GTV, gross tumor volume; V20, volume of lung receiving at least 20 Gy; MLD, mean lung dose; PET, positron emission thermography.