Propensity score-based comparison of survival and radiation pneumonitis after definitive chemoradiation for esophageal cancer: Intensity-modulated radiotherapy versus three-dimensional conformal radiotherapy.

•Compared with three-dimensional conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT) was significantly associated with better overall survival, progression-free survival, and distant metastasis-free survival in patients with esophageal squamous cell carcinoma who underwent definitive chemoradiation therapy.•IMRT demonstrated a significantly lower risk of symptomatic radiation pneumonitis than 3DCRT.•According to logistic regression model, the risk of radiation pneumonitis increased with primary tumor length, planning target volume, and lung V20, but this trend was much more pronounced with 3DCRT.