Long-term follow-up of a phase I/II trial of radiation dose escalation by simultaneous integrated boost for locally advanced esophageal squamous cell carcinoma

Background To observe the long-term survival and late adverse events in a phase Ⅰ/Ⅱ trial (NCT01843049) of dose escalation for thoracic esophageal squamous cell carcinoma (ESCC) with simultaneous integrated boost (SIB) technique. Methods Patients with ESCC were treated with escalating radiation dose of four predefined levels. Dose of 62.5–64 Gy/25–32 fractions was delivered to the gross tumor volume (GTV), with (Level 3&4) or without (Level 1&2)...