Through a study of 85 patients with moderate and low rectal cancer who received radiation therapy with a linear accelerator at a dose of 50.4 Gy and capecitabine before surgery, the results: - 100% of patients have a functional response after chemotherapy and radiotherapy - 3.5% of patients had a complete response, 81.2% had a partial response, 15.3% - The 5-year overall survival time reached 81.2%, the average was 59.9±1.72 months - 5-year disease-free survival time reached 74.1%, average 52.3 ± 2.14 months.