Table 4.
Prognostic factors for grade ≥ 3 acute esophagitis and grade ≥ 2 radiation pneumonitis.
| Grade ≥ 3 Acute Esophagitis | Univariable Analysis | Multivariable Analysis | |||||
| Variables | (Reference vs.) | OR | (95% CI) | p -Value | OR | (95% CI) | p -Value |
| RT modality | (IMRT vs. PBSPT) | 2.78 | (0.84–8.00) | 0.070 | 3.68 | (0.97–12.88) | 0.045 |
| Sex | (female vs. male) | 0.33 | (0.13–0.85) | 0.019 | 0.32 | (0.06–1.74) | 0.181 |
| Age | (<65 vs. ≥65 years) | 1.2 | (0.47–2.98) | 0.698 | |||
| Smoking history | (never vs. ever) | 0.39 | (0.15–1.04) | 0.049 | 0.74 | (0.13–4.30) | 0.735 |
| Clinical T stage | (T1–2 vs. T3–4) | 0.89 | (0.33–2.26) | 0.818 | |||
| Clinical N stage | (N2 vs. N3) | 0.53 | (0.21–1.35) | 0.170 | |||
| Contralateral mediastinal lymph node |
(no vs. yes) | 0.89 | (0.34–2.21) | 0.803 | |||
| SCF lymph node | (no vs. yes) | 0.86 | (0.31–2.16) | 0.749 | |||
| PTV | (<550 vs. ≥550 cc) | 1.39 | (0.56–3.54) | 0.479 | |||
| Fractional RT dose | (2.0 vs. 2.2 GyE) | 2.37 | (0.76–10.38) | 0.181 | |||
| Total RT dose | (≤66 vs. >66 GyE) | 0.69 | (0.27–1.66) | 0.408 | |||
| Esophagus Dmax | (<70 vs. ≥70 GyE) | 2.65 | (0.94–9.46) | 0.090 | 2.46 | (0.68–10.66) | 0.193 |
| Esophagus V45GyE | (<35 vs. ≥35%) | 4.33 | (1.73–11.50) | 0.002 | 3.98 | (1.12–19.02) | 0.049 |
| Esophagus V55GyE | (<20 vs. ≥20%) | 3.14 | (1.18–9.89) | 0.032 | 0.76 | (0.13–3.69) | 0.736 |
| Esophagus V66GyE | (<10 vs. ≥10%) | 2.05 | (0.83–5.24) | 0.122 | |||
| Grade ≥ 2 radiation pneumonitis | Univariable analysis | Multivariable analysis | |||||
| Variables | (reference vs.) | OR | (95% CI) | p -value | OR | (95% CI) | p -value |
| RT modality | (IMRT vs. PBSPT) | 0.47 | (0.13–1.30) | 0.183 | 0.88 | (0.24–2.64) | 0.837 |
| Sex | (female vs. male) | 0.69 | (0.35–1.41) | 0.298 | |||
| Age | (<65 vs. ≥65 years) | 1.07 | (0.58–1.96) | 0.825 | |||
| Smoking history | (never vs. ever) | 0.64 | (0.32–1.30) | 0.208 | |||
| Clinical T stage | (T1–2 vs. T3–4) | 1.06 | (0.57–1.96) | 0.842 | |||
| Clinical N stage | (N2 vs. N3) | 0.64 | (0.32–1.21) | 0.166 | |||
| Contralateral mediastinal lymph node |
(no vs. yes) | 0.72 | (0.38–1.32) | 0.298 | |||
| SCF lymph node | (no vs. yes) | 1.01 | (0.54–1.86) | 0.979 | |||
| FEV1 (%) | (≥70 vs. <70%) | 0.80 | (0.38–1.59) | 0.529 | |||
| DLco (%) | (≥60 vs. <60%) | 0.86 | (0.38–1.84) | 0.707 | |||
| PTV | (<550 vs. ≥550 cc) | 1.61 | (0.89–2.95) | 0.121 | |||
| Fractional RT dose | (2.0 vs. 2.2 GyE) | 1.15 | (0.59–2.32) | 0.691 | |||
| Total RT dose | (≤66 vs. >66 GyE) | 0.76 | (0.24–2.03) | 0.605 | |||
| Both-lung Dmean | (<20 vs. ≥20 GyE) | 2.79 | (1.51–5.19) | 0.001 | 1.71 | (0.62–4.74) | 0.297 |
| Both-lung V5GyE | (<65 vs. ≥65%) | 1.86 | (0.90–3.76) | 0.087 | 0.61 | (0.24–1.51) | 0.292 |
| Both-lung V10GyE | (<45 vs. ≥45%) | 3.78 | (2.04–7.10) | <0.001 | 4.37 | (1.63–12.12) | 0.004 |
| Both-lung V20GyE | (<35 vs. ≥35%) | 2.60 | (1.40–4.86) | 0.003 | 0.69 | (0.20–2.23) | 0.542 |
The foreparts of the parentheses were set as the reference group. Abbreviations: OR, odds ratio; CI, confidence interval; RT, radiation therapy; IMRT, intensity-modulated radiation therapy; PBSPT, pencil beam scanning proton therapy; SCF, supraclavicular fossa; FEV1, forced expiratory volume in 1 s; DLco, diffusing capacity of the lung for carbon monoxide; PTV, planning target volume; GyE, gray relative biologic effectiveness; BED10, biological effective dose with α/β of 10; VXXGyE = volume receiving more than XX GyE.