Moderately Hypofractionated Conformal Radiation Combined With S-1 for Esophageal Squamous Cell Carcinoma

Inclusion Criteria: * Histologically confirmed esophageal squamous cell carcinoma * Inoperable stage II-IVa (UICC 2002; sixth edition), confirmed by contrast enhanced computed tomography,endoscopic ultrasonography, barium esophagram, emission computed tomography and/or positron emission tomography/computed tomography. * Eastern Cooperative Oncology Group (ECOG) performance status 1-2 * Estimated life expectancy of at least 12 weeks * Charlson comorbidity index.4 * Adequate bone marrow function: white blood cells grade 0 or 1,absolute neutrophils grade 0 or 1, platelets grade 0, haemoglobin grade 0 or 1 * Adequate renal function: creatinine grade 0 or 1 * Adequate liver function: serum bilirubin grade 0 or 1, alanine aminotransferase and aspartate aminotransferase \<2 times of the upper normal limit * Weight loss.15% during 6 months prior to diagnosis * Forced expiratory volume second.1L Exclusion Criteria: * Prior history of malignancy, except for nonmelanoma skin carcinoma or cervical carcinoma in situ * Previous anti-tumor therapy, including surgery, chemotherapy or radiotherapy * Contraindication for chemotherapy or radiotherapy * Malignant pleural or pericardial effusion * Women in pregnancy or lactation period * Women who has the probability of pregnancy without contraception * Weight loss≥15% during 3 months prior to diagnosis * In other clinical trials within 30 days * Addicted in drugs or alcohol, AIDS patients * Uncontrollable seizure or psychotic patients without self-control ability * Severe allergy or idiosyncrasy * Not suitable for this study judged by researchers