Table 3.
Univariate Cox Regression of Clinical and Dosimetric Factors for Risk of ≥ Grade 2 RP
| Total Patients (n=136) |
Patients with ≥Grade 2 RP (n=40) |
Percent of Patients with ≥Grade 2 RP |
HR | 95% CI | p-value | |
|---|---|---|---|---|---|---|
|
| ||||||
| Patient Characteristics | ||||||
|
| ||||||
| Age<66 | 64 | 17 | 26.6% | 1.0* | - | - |
| Age≥66 | 72 | 23 | 31.9% | 1.25 | 0.67-2.33 | 0.49 |
|
| ||||||
| Male | 67 | 26 | 38.8% | 2.22 | 1.16-4.26 | 0.017 |
| Female | 69 | 14 | 20.3% | 1.0* | - | - |
|
| ||||||
| ECOG PS | ||||||
| 0 | 62 | 17 | 27.4% | 1.0* | - | - |
| 1 | 67 | 18 | 26.9% | 1.01 | 0.52-1.96 | 0.98 |
| 2 | 7 | 5 | 71.4% | 3.63 | 1.34-9.87 | 0.01 |
|
| ||||||
| Smoking Status | ||||||
| Current | 48 | 11 | 22.9% | 1.0* | - | - |
| Former | 74 | 26 | 35.1% | 1.62 | 0.80-3.29 | 0.18 |
| Never | 14 | 3 | 21.4% | 0.92 | 0.26-3.31 | 0.90 |
|
| ||||||
| Pack-year<49 | 68 | 20 | 29.4% | 1.0* | - | - |
| Pack-years≥49 | 68 | 20 | 29.4% | 0.98 | 0.53-1.82 | 0.95 |
|
| ||||||
| FEV1<1.98 L | 78 | 55 | 70.5% | 1.0* | - | - |
| FEV1≥1.98 L | 58 | 41 | 70.7% | 0.99 | 0.53-1.85 | 0.97 |
|
| ||||||
| Tumor Characteristics | ||||||
|
| ||||||
| Histology: | ||||||
| SCC | 29 | 10 | 34.5% | 0.96 | 0.32-2.90 | 0.95 |
| AdenoCA | 64 | 15 | 23.5% | 1.0* | - | - |
| Carcinoma NOS | 28 | 11 | 39.3% | 1.53 | 0.69-3.40 | 0.30 |
| SCLC | 15 | 4 | 26.7% | 1.68 | 0.77-3.65 | 0.19 |
|
| ||||||
| T-stage | ||||||
| 0-1 | 37 | 7 | 18.9% | 0.62 | 0.31-1.24 | 0.17 |
| 2 | 47 | 17 | 36.2% | 1.0* | - | - |
| 3 | 24 | 9 | 37.5% | 1.19 | 0.60-2.38 | 0.62 |
| 4 | 28 | 7 | 25.0% | 0.84 | 0.39-1.84 | 0.67 |
|
| ||||||
| N-stage | ||||||
| 0-1 | 21 | 1 | 4.8% | 0.33 | 0.14-0.79 | 0.01 |
| 2 | 80 | 27 | 33.8% | 1.0* | - | - |
| 3 | 35 | 12 | 34.3% | 0.99 | 0.53-1.84 | 0.98 |
|
| ||||||
| Stage | ||||||
| IIB | 9 | 0 | 0% | 0.0 | 0.0 | 0.99 |
| IIIA | 63 | 23 | 36.5% | 1.0* | - | - |
| IIIB | 52 | 14 | 26.9% | 0.75 | 0.38-1.44 | 0.37 |
| IV | 12 | 3 | 25.0% | 0.70 | 0.21-2.33 | 0.56 |
|
| ||||||
| Treatment Characteristics | ||||||
|
| ||||||
| Radiation Dose | ||||||
| <60 Gy | 35 | 6 | 24.0% | 0.70 | 0.25-1.92 | 0.49 |
| ≥60 Gy and >66 Gy | 40 | 10 | 25.0% | 1.0* | - | - |
| ≥66 Gy and >70 Gy | 28 | 12 | 42.8% | 1.86 | 0.80-4.31 | 0.15 |
| ≥70 Gy | 33 | 12 | 36.4% | 1.63 | 0.70-3.78 | 0.25 |
|
| ||||||
| Radiation Technique: | ||||||
| 3D Conformal | 34 | 8 | 23.5% | 0.73 | 0.34-1.59 | 0.43 |
| IMRT | 102 | 32 | 31.4% | 1.0* | - | - |
|
| ||||||
| Simulation Technique: | ||||||
| 3D-CT | 72 | 19 | 26.4% | 1.0* | - | - |
| 4D CT | 64 | 21 | 32.8% | 1.28 | 0.69-2.39 | 0.43 |
|
| ||||||
| Radiation Sequencing: | ||||||
| Pre-operative | 15 | 2 | 13.3% | 0.30 | 0.07-1.24 | 0.10 |
| Radiation alone | 106 | 37 | 34.9% | 1.0* | - | - |
| Post-operative | 15 | 1 | 6.7% | 0.17 | 0.02-1.25 | 0.08 |
|
| ||||||
| Surgery | 30 | 3 | 10.0% | 0.23 | 0.07-0.74 | 0.014 |
|
| ||||||
| Any Chemotherapy | 130 | 39 | 30.0% | 1.66 | 0.23-12.08 | 0.62 |
|
| ||||||
| Concurrent Chemotherapy | 121 | 39 | 32.2% | 5.27 | 0.72-38.35 | 0.10 |
|
| ||||||
| Consolidation Chemotherapy | 78 | 24 | 30.8% | 1.0 | 0.84-1.18 | 0.96 |
|
| ||||||
| Consolidation Docetaxel | 16 | 8 | 50.0% | 2.11 | 0.97-4.58 | 0.06 |
|
| ||||||
|
Bilateral Lung Dose-
Volume Histogram |
||||||
|
| ||||||
| V5<60% | 62 | 13 | 21.0% | 1.0* | - | - |
|
| ||||||
| V5≥60% | 74 | 27 | 36.4% | 1.90 | 0.98-3.69 | 0.057 |
|
| ||||||
| V20<30% | 52 | 9 | 17.3% | 0.45 | 0.20-1.04 | 0.061 |
| V20≥30% and <40% | 43 | 15 | 34.9% | 1.0* | - | - |
| V20≥40% | 41 | 16 | 39.0% | 1.15 | 0.57-2.33 | 0.70 |
|
| ||||||
| MLD<18 Gy | 66 | 14 | 21.2% | 1.0* | - | - |
| MLD≥18 Gy | 70 | 26 | 37.1% | 1.95 | 1.02-3.74 | 0.044 |
*
Reference group for Cox regression
Abbreviations: CI=confidence interval; CT=computed tomography; FEV1=force expiratory volume in 1 second; HR=hazard ratio; IMRT=intensity modulated radiation therapy; MLD=mean lung dose; PS=performance status; RP=radiation pneumonitis; V5=volume receiving greater than 5 Gy; V10=volume receiving greater than 10 Gy; V20=volume receiving greater than 20 Gy.