Radical radiotherapy refers to the application of tumor-lethal amount of radiation to completely destroy the primary and metastatic lesions of malignant tumors. It is mainly applied to tumors that are sensitive or moderately sensitive to radiation (tumors that can be eliminated by 20-40 Gorey rays are radiosensitive tumors, tumors that can be eliminated by 60 Gorey rays are moderately sensitive tumors, and tumors that cannot be eliminated by rays exceeding 60 Gorey or exceeding the normal tissue tolerance are insensitive tumors, also known as refractory tumors). The radiation dose applied in clinical practice is based on the radical dose required by different tumor tissues. For example, the radical dose for Hodgkin’s disease is 40Gray/5-6 weeks (whole lymph node area irradiation), nasopharyngeal carcinoma is generally 60-70Gray/7 weeks, vocal cord carcinoma is 60-70Gray/6-8 weeks, and lung squamous carcinoma and esophageal carcinoma is 60Gray/6 weeks. Palliative radiotherapy refers to radiation therapy aimed at relieving pain, improving symptoms and prolonging the life of patients with advanced malignant tumors. Clinically, it can be subdivided into two types: highly palliative and low palliative. High palliative treatment is used for patients with good general condition, and the dose given is radical or near radical. Palliative radiotherapy has the following effects: ① Pain relief: Bone metastasis and soft tissue infiltration can cause severe pain, such as breast cancer bone metastasis, pancreatic cancer invasion of the posterior abdominal wall nerve and anal canal and pelvic metastasis of rectal cancer, etc. ② Relieve compression symptoms: gastrointestinal obstruction caused by malignant tumors, superior vena cava syndrome caused by lung cancer or mediastinal tumors, urinary system obstruction caused by abdominal tumors, and cerebral neurological symptoms caused by brain-occupying lesions, etc. ③Promote healing of lesions: skin cancer, oral cancer, penile cancer, breast cancer, etc. are often accompanied by large ulcers of tissues, and radiotherapy can shrink lesions and promote their healing. ④Control the development of distant metastases: such as lung cancer, lymph node metastasis in the neck of breast cancer or small nodal metastases in the satellite of breast cancer. ⑤ Stopping bleeding: such as bleeding from nasopharyngeal cancer. Of course, the so-called radical and palliative radiotherapy are relative and cannot be generalized. Radical radiotherapy may sometimes fail to achieve radical effect, while palliative radiotherapy can sometimes achieve unexpected curative effect. In addition, because radiation-sensitive tumors are often of high malignancy and early metastasis, although the tumors are controlled locally, they often die due to distant metastasis, and the recurrence rate of these tumors after radiation therapy is high. Clinical experience proves that most of the tumors cured by radiation therapy are tumors with moderate sensitivity to radiation.