Three-dimensional conformal radiation therapy alone for esophageal squamous cell carcinoma: 10-year survival outcomes.

BACKGROUND: Concurrent chemoradiation is the standard treatment for locally advanced esophageal squamous cell carcinoma (SCC). We conducted a phase II study to explore the effect of three-dimensional conformal radiotherapy (3-DCRT) alone for patients with locally advanced esophageal SCC. This study aimed to analyze the long-term survival outcomes. METHODS: Between November 2004 and April 2007, 30 patients with thoracic esophageal SCC underwent late-course sequential boost 3-DCRT at Fudan University Shanghai Cancer Center. The planning target volume (PTV1) comprised a 1.2-1.5 cm lateral margin around the gross tumor volume and a 3.0 cm margin, superior and inferior to the gross tumor volume. PTV2 encompassed the gross tumor volume with a margin of 0.5-0.7 cm. The PTV1 dose delivered was 50 Gy, and the PTV2 dose was a boost dose of 16 Gy, resulting in a total dose of 66 Gy. No chemotherapy was administered. RESULTS: The median follow-up time was 30 months for all patients, and 132 months for patients who were alive. The median overall survival was 27 months (95% confidence interval [CI] 18.9-35.0). The 2-, 5-, and 10-year overall survival rates were 56.6%, 33.3%, and 26.6%, respectively. The median progression-free survival was 14 months (95% CI 7.7-20.2 months), and the 2-, 5-, and 10-year progression-free survival rates were 33.3%, 30.0%, and 26.6%, respectively. No severe late toxicity was observed in long-term survivors. CONCLUSION: Late-course sequential boost 3-DCRT is safe and feasible with promising long-term outcomes for esophageal SCC.