Radiotherapy is a commonly used form of anti-tumor treatment, which belongs to a kind of local treatment. It is a method of treating tumors using radiation, which includes alpha, beta and gamma rays produced by radioisotopes, x-rays produced by various types of x-ray therapy machines or gas pedals, electron beams, proton beams, and some other particle beams and so on. About 70% of cancer patients need to use radiotherapy in the treatment of cancer. Some cancers, about 40%, may be cured by radiotherapy, for example, nasopharyngeal cancer can be cured by radiotherapy. Generally speaking, the side effects of radiotherapy are mainly radiation enteritis, radiation pneumonia and so on, and there are some differences in the side effects according to the different sites of radiotherapy. For example, breast cancer may have radioactive pneumonia and skin damage after radiotherapy; pelvic tumors may have radioactive enteritis after radiotherapy, which may get better slowly through symptomatic treatment. Others may be similar to chemotherapy, and may produce bone marrow suppression.