Radiotherapy and chemotherapy are commonly used in the treatment of tumors, and each has its own advantages. Different treatment methods: radiotherapy, that is, radiotherapy, is a treatment method that irradiates tumors with different energy rays to inhibit and kill cancer cells, commonly known as "baking electricity". Chemotherapy is the application of chemical drugs (including endocrine drugs, etc. ) to treat malignant tumors. Chemotherapeutic drugs usually kill tumors by intravenous injection, oral administration or other forms. Different treatment ranges: radiotherapy, like surgery, is mainly local treatment. The range of radiotherapy is called "target area", that is, the area where radiation is concentrated, and there is not much radiation outside the target area. After radiologists determine the tumor size and invasion site according to imaging and other clinical examinations, they must also understand the biological characteristics and diffusion law of the tumor before deciding the irradiation range. Chemotherapy is mainly systemic therapy, and the drugs will be distributed all over the body after entering the body, which not only has an effect on solid tumors, but also has a strong killing effect on tiny invisible metastases. Of course, there are also local chemotherapy such as interventional chemotherapy and local perfusion chemotherapy. Different indications: radiotherapy is mainly aimed at radical treatment of relatively limited solid tumors, such as head and neck tumors, lung cancer, esophageal cancer, skin cancer, lymphoma, etc. Preoperative and postoperative adjuvant therapy for some tumors, such as breast cancer, cervical cancer and gastrointestinal tumors; In addition, palliative radiotherapy for some tumors, such as bone and brain metastases, has limited curative effect on systemic tumors such as leukemia. At present, about 70% of tumor patients need radiotherapy at different stages of the disease course, which shows the importance of radiotherapy in tumor treatment. Chemotherapy is aimed at tumors sensitive to chemotherapeutic drugs, such as lymphoma, leukemia and other hematological diseases, breast cancer, gastrointestinal tumors, lung cancer, reproductive system tumors and so on. The effect of chemotherapy depends on the type and condition of the tumor, some can be cured, and more is to inhibit the growth and spread of the tumor. With the emergence of new technology, the indications of radiotherapy and chemotherapy are also changing. Different toxic and side effects: generally speaking, radiotherapy is mainly a local reaction, which is related to the irradiation field. For example, head and neck radiotherapy can cause dry mouth, sore throat, cervical fibrosis, decreased taste function and so on. Radioactive lung changes and radiation esophagitis may occur during chest radiotherapy. With the development of radiotherapy technology, radiation-induced brain injury and paraplegia, which used to occur frequently, are less common. Chemotherapy is dominated by systemic reactions, generally bone marrow suppression and gastrointestinal reactions, such as hemogram reduction, nausea, vomiting, phlebitis and so on. As long as it is handled properly, severe liver and kidney function damage, cardiac function damage and other violent reactions are not very common in clinic. Now that technology is developing, the side effects of radiotherapy and chemotherapy are gradually decreasing.