Table 3. Logistic regression analysis for radiation pneumonitis ≥ grade 3 (n=18).
| Characteristic | n | Univariate analysis | Multivariate analysis | |||||
|---|---|---|---|---|---|---|---|---|
| HR | 95% CI | P value | HR | 95% CI | P value | |||
| Age | 1.00 | 0.94–1.07 | 1.00 | – | – | – | ||
| Gender | 0.39 | |||||||
| Male | 408 | 1 | – | – | – | – | – | |
| Female | 173 | 1.52 | 0.55–3.93 | – | – | – | ||
| Pack–years | 0.85 | |||||||
| <20 | 186 | 1.00 | – | – | – | – | – | |
| 20–50 | 195 | 0.81 | 0.26–2.49 | 0.71 | – | – | – | |
| >50 | 184 | 0.71 | 0.21–2.28 | 0.57 | – | – | – | |
| PTV | – | 1.01 | 1.00–1.02 | 0.07 | – | – | – | |
| T stage | 0.15 | |||||||
| T1a–b | 328 | 1 | – | – | – | – | – | |
| T2a–b | 167 | 2.01 | 0.72–5.56 | 0.17 | – | – | – | |
| T3–4 | 48 | 0.00 | blank–1.85 | 0.13 | – | – | – | |
| rT1–4 | 38 | 2.22 | 0.33–9.29 | 0.36 | – | – | – | |
| Histology | 0.79 | – | ||||||
| Proven NSCLC | 308 | 1 | – | – | – | – | – | |
| Clinical NSCLC | 273 | 1.13 | 0.44–2.94 | – | – | – | – | |
| Location | 0.89 | – | – | – | ||||
| Peripheral | 411 | 1 | – | – | – | – | – | |
| Central | 170 | 0.93 | 0.29–2.50 | – | – | – | – | |
| %VC | 0.14 | 0.09 | ||||||
| 80–140 | 292 | 1 | – | – | 1.00 | – | – | |
| 70–79 | 151 | 0.83 | 0.18–3.02 | 0.78 | 0.78 | 0.16–2.92 | 0.73 | |
| −69 + unmeasurable | 138 | 2.51 | 0.88–7.29 | 0.37 | 2.82 | 0.97–8.42 | 0.06 | |
| GOLD | 0.19 | |||||||
| Non–COPD | 295 | 1 | – | – | – | – | – | |
| I–II | 166 | 0.31 | 0.05–1.19 | 0.09 | – | – | – | |
| III–IV + unmeasurable | 120 | 1.12 | 0.35–3.16 | 0.83 | – | – | – | |
| Total dose | 0.36 | |||||||
| 60 Gy | 72 | 0.36 | 0.02–1.83 | 0.26 | – | – | – | |
| 50 Gy | 401 | 1 | – | – | – | – | – | |
| 40 Gy | 108 | 0.49 | 0.08–1.76 | – | – | – | – | |
| V20 | 1.14 | 1.02–1.26 | <0.05 | 1.14 | 1.02–1.27 | 0.03 | ||
| MLD | 1.44 | 1.16–1.77 | <0.01 | – | – | – | ||
| Predictable high–risk RP factors | 0.08 | 0.03 | ||||||
| No | 404 | 1 | – | – | 1 | – | – | |
| Yes | 177 | 2.35 | 0.90–6.12 | 3.11 | 1.15–8.48 | |||
| Idiopathic interstitial pneumonias | <0.01 | |||||||
| No | 536 | 1 | – | – | – | – | – | |
| Yes | 45 | 6.72 | 2.24–18.30 | – | – | – | – | |
| Elevated KL–6/SP–D | 0.12 | |||||||
| No | 420 | 1 | – | – | – | – | – | |
| Yes | 161 | 2.14 | 0.80–5.53 | – | – | – | – | |
| CAM administration | 0.24 | |||||||
| No | 487 | 1 | – | – | – | – | – | |
| Yes | 94 | 0.30 | 0.02–1.48 | – | – | – | – | |
| Era | 0.10 | 0.02 | ||||||
| Non–CAM era | 445 | 1 | – | – | 1 | – | – | |
| CAM era | 136 | 0.19 | 0.01–0.92 | – | 0.14 | 0.01–0.75 | – | |
HR, hazard ratio; CI, confidence interval; PTV, planning target volume; NSCLC, non-small cell lung cancer; %VC, vital capacity as percent of predicted; GOLD, global initiative for chronic obstructive lung diseases stage; V20, the normal lung volume receiving ≥20 Gy; MLD, mean normal lung dose; RP, radiation pneumonitis; KL–6, sialylated carbohydrate antigen; SP-D, surfactant protein D; CAM, clarithromycin.