Intensity-Modulated Radiotherapy versus Three-Dimensional Conformal Radiotherapy in Definitive Chemoradiotherapy for Cervical Esophageal Squamous Cell Carcinoma: Comparison of Survival Outcomes and Toxicities.

ABSTRACT

PURPOSE: The purpose of this study was to compare the survival and toxicities in cervical esophageal squamous cell carcinoma (CESCC) treated by concurrent chemoradiothrapy with either three-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) techniques. MATERIALS AND METHODS: A total of 112 consecutive CESCC patients were retrospectively reviewed. 3D-CRT and IMRT groups had been analyzed by propensity score matching method, with sex, age, Karnofsky performance status, induction chemotherapy, and tumor stage well matched. The Kaplan-Meier method and Cox proportional hazards model were used for overall survival (OS) and progression-free survival (PFS). Toxicities were compared between two groups by Fisher exact test. RESULTS: With a median follow-up time of 34.9 months, the 3-year OS (p=0.927) and PFS (p=0.859) rate was 49.6% and 45.8% in 3D-CRT group, compared with 54.4% and 42.8% in IMRT group. The rates of grade ≥ 3 esophagitis, grade ≥ 2 pneumonitis, esophageal stricture, and hemorrhage were comparable between two groups, while the rate of tracheostomy dependence was much higher in IMRT group than 3D-CRT group (14.3% vs.1.8%, p=0.032). Radiotherapy technique (hazard ratio [HR], 0.09; 95% confidence interval [CI], 0.01 to 0.79) and pretreatment hoarseness (HR, 0.12; 95% CI 0.02 to 0.70) were independently prognostic of tracheostomy dependence. CONCLUSION: No survival benefits had been observed while comparing IMRT versus 3D-CRT in CESCC patients. IMRT with fraction dose escalation and pretreatment hoarseness were considered to be associated with a higher risk for tracheostomy dependence. Radiation dose escalation beyond 60 Gy should be taken into account carefully when using IMRT with hypofractionated regimen.