Radiation therapy is a method of treating various tumors with radiation, which is commonly used to treat various malignant tumors, but it is important to note that there are adverse effects. These rays, which are invisible to the naked eye, are produced by radiation therapy machines and penetrate the body to the tumor site to kill the tumor cells. Radiotherapy is an important method used in the treatment of many malignant tumors, and can play a good role in adjuvant therapy. However, radiotherapy can produce some adverse effects, such as blood cell drop, nausea, vomiting, loss of appetite, diarrhea, abdominal pain and other side effects, which can be effectively eliminated through adjuvant supportive therapy. Radiotherapy has good therapeutic effect on many kinds of tumors, but it should be noted that the treatment should be based on the specific situation. For one thing, radiotherapy is a local treatment, which is not suitable if the tumor is extensive, and also some tumors are insensitive to radiotherapy leading to poor efficacy.