The duration of one course of radiotherapy ranges from 4 to 7 weeks, and the specific duration of radiotherapy is related to the site of radiotherapy and the purpose of radiotherapy. 1. Related to radiotherapy site: the time required for a course of radiotherapy varies depending on the site where each person needs radiotherapy, for example, a course of radiotherapy for nasopharyngeal cancer is about 7 weeks, postoperative adjuvant radiotherapy for rectal cancer is about 5 weeks, and radiotherapy for cervical esophageal cancer is about 6 weeks, and so on. 2. Related to the purpose of radiotherapy: radiotherapy can be divided into preoperative radiotherapy, postoperative radiotherapy, radical radiotherapy and palliative radiotherapy. Usually, a course of preoperative radiotherapy takes about 4 weeks; a course of postoperative radiotherapy and palliative radiotherapy takes about 5 weeks; radical radiotherapy takes a longer time and may take about 6-7 weeks. Before radiotherapy, you should go to a regular hospital to complete the examination, make a clear diagnosis, and carry out the treatment under the guidance of the physician; if the discomfort is more serious in the course of radiotherapy, you should contact the physician in time in order to adjust the program.