Radical radiotherapy (1) Indications: general condition is moderate or above, lesion length ≤ 7cm, no obvious invasion, perforation and extensive metastasis of surrounding lymph nodes on X-ray barium meal and CT (or MRI), no vocal cord paralysis, severe pain behind the sternum, supraclavicular lymph nodes and other distant metastases. (2) Radiotherapy design: 3 field irradiation technique is often used in radiotherapy for esophageal cancer, and the length of the field is usually 3 cm longer than each end of the lesion. in recent years, the application of intensity-modulated radiotherapy has greatly reduced the adverse effects of radiotherapy for esophageal cancer, improved the patient’s treatment tolerance and ensured the efficacy. (3) Dose and duration of irradiation: conventional irradiation protocol is 1.8-2.0GY/time, once a day, 5 times/week, total dose DT60-70GY/6-7 weeks. (4) The most important reason for failure of radiotherapy for esophageal cancer is uncontrolled local lesions and recurrence, which accounts for about 90%. (5) Intraluminal therapy: Intraluminal therapy is generally used as a complementary means to external irradiation for esophageal cancer, in the hope of increasing the local dose to achieve improved survival, local control rate and reduced recurrence rate. Sometimes, it is also used as palliative reduction treatment for advanced esophageal cancer with significant obstruction and bleeding. Preoperative radiotherapy for esophageal cancer is designed to shrink local tumor, improve cancerous adhesions in surrounding tissues, and kill subclinical lesions to improve surgical resection rate and reduce recurrence rate. The field design and dose splitting of preoperative radiotherapy are the same as that of radical radiotherapy, and the preoperative radiotherapy dose is usually DT40-50GY/4-5 weeks, with 4-6 weeks rest before surgical resection. Postoperative radiotherapy is not beneficial after surgery. Currently, postoperative radiotherapy is usually given only when the following conditions occur: (1) palliative surgery with cancer residue visible to the naked eye; (2) cancer infiltration in postoperative stump; (3) incomplete intraoperative lymph node dissection around esophagus; (4) postoperative estimation of possible subclinical lesions that are prone to recurrence. Postoperative radiotherapy should be given at doses ranging from 50-70 GY depending on the residual cancer. Palliative radiotherapy For advanced esophageal cancer with no indication of radical treatment, local palliative radiotherapy can be given to relieve the symptoms of feeding obstruction. Radiotherapy CT localization