Abstract: Objective To evaluate the efficacy and toxic effects of intensity modulated radiation therapy(IMRT) combined with tegafur(S-1) in the elderly patients with esophageal cancer. Methods This was a single-arm, phase Ⅱ clinical study. A total of 120 elderly patients with esophageal squamous cell carcinoma aged ≥75 years old from May 2014 to April 2021 were recruited. The IMRT and chemotherapy were conducted. The adverse reactions and curative effects were observed. Results The median follow-up time was 41.2 months (5.9-90.4 months) by October 2021. One-, two- and three-year overall survival rate was 81.1%, 64.8%, and 48.0%, respectively. One-, two- and three-year progression-free survival rate was 77.6%, 53.4%, and 39.3%, respectively. One-, two- and three-year tumor specific overall survival rate was 88.2%, 78.5%, and 64.1%, respectively. The main toxic and side effects above grade 3 were hematological reactions, including grade 3 hemoglobin decreased in 1 case (0.8%), grade 3 leukocyte decreased in 9 cases (7.5%), grade 4 leukocyte decreased in 2 cases (1.7%), grade 3 granulocyte decreased in 3 cases (2.5%), grade 4 leukocyte decreased in 1 case (0.8%), and grade 3 platelet decreased in 4 cases (3.3%). Conclusions Involving field radiotherapy combined with concurrent chemotherapy with S-1 is safe and effective in the elderly patients with esophageal squamous cell carcinoma, and the toxic and side effects are tolerable. It is worthy of further phase Ⅲ clinical study.

Key words: esophageal cell carcinoma, intensity-modulated radiotherapy, tegafur