Purpose: To evaluate the clinical efficacy and toxicity of simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) in patients with esophageal squamous cell carcinoma (ESCC) in Chinese population.
Patients and methods: Patients with ESCC, who received SIB-IMRT from September 2011 to January 2013 were retrospectively analyzed. The SIB-IMRT plans were designed to deliver primary gross tumor volume at 60-64.4 Gy in 28-30 fractions, and planning target volume at 50.4-56 Gy in 28-30 fractions. Treatment-related toxicities were estimated based on Common Terminology Criteria for Adverse Events version 4.0, and tumor response after the treatment was estimated according to Response Evaluation Criteria in Solid Tumors version 1.0. Overall survival (OS), locoregional progression-free survival (LPFS), and progression-free survival (PFS) were estimated with Kaplan-Meier.
Results: All patients completed definitive radiotherapy, 54 (78.3%) received combined chemotherapy, of which 31 (44.9%) were concurrent chemoradiotherapy and 23 (33.3%) were sequential chemotherapy. The objective response rate is 82.6% (56/69), with complete response 11 (15.9%), partial response 45 (65.2%), stable disease 8 (11.6%), and progressive disease 5 (7.2%). The 1-, 2- and 3-year LPFS was 74.4%, 57.8%, and 55.6%, respectively. The 1-, 2- and 3-year PFS was 62.3%, 41.0%, and 34.2%, respectively, and the 1-, 2-, and 3-year OS was 73.8%, 57.4%, and 41.0%, respectively, with a median OS of 27.1 months (4.5-54.9 m). For those who received concurrent chemotherapy, the 1-, 2-, and 3-year OS was 75.9%, 69.0%, and 55.2%, respectively, better than those who had sequential chemotherapy or radiotherapy alone (χ2 = 3.115, P = 0.078). Radiation esophagitis occurred in 63.8% and 14.5% with Grade 2 and 3, respectively. No patients occurred ≥ Grade 3 radiation pneumonia.
Conclusions: It is safe and effective using SIB-IMRT technology to treat patients with ESCC. More prospective clinical studies should be needed.