Abstract: Objective: To compare the efficacy and prognosis survival of definitive concurrent chemoradiotherapy with different radiotherapy target volumes in elderly patients over 70 years old with locally advanced thoracic esophageal squamous cell carcinoma. Methods: A retrospective analysis was conducted on the clinical data of 94 elderly patients over 70 years old with locally advanced thoracic esophageal squamous cell carcinoma who received definitive concurrent chemoradiotherapy from 2021 to 2023.According to the different ranges of clinical target volume(CTV), the patients were divided into the control group and observation group(47 cases in each group).The control group was given the selective lymph node drainage area irradiation protocol, while the observation group was given the lymph node involvement field irradiation model.The treatment data of the therapeutic effects, survival expectation, dosimetric indicators and adverse reactions between two groups were compared. Results: There was no statistically significance in the objective remission rate and disease control rate between two groups(P>0.05).The incidence of serious adverse reactions in the observation group was lower than that in control group(P < 0.05).There was no statistically significance in the survival curves between two groups(P>0.05).There was no statistically significance in the average dose and uniformity indicators of the planned target vaume between two groups(P>0.05).The observation group had better target volume conformity indicators compared to the control group (P < 0.05), while the levels of V5 in both lungs, V30 in the heart, and V40 in the heart were lower than those in control group(P < 0.05 to P < 0.01). Conclusions: Two different radiotherapy strategies enable patients to achieve comparable therapeutic effects and survival times.However, lymph node involvement field irradiation model has more adverse reactions, and the safety for organs such as the heart and lungs is higher.