Radical radiotherapy can be used as a radical treatment when the tumor is limited, or only adjacent tissue invasion or lymph node metastasis, and the tumor is more sensitive to radiation. Such as nasopharyngeal cancer and other head and neck tumors, lung cancer, esophageal cancer, lymphatic system malignant tumors, prostate cancer, cervical cancer, etc. Early stage breast cancer can be treated by local surgical excision with radical radiotherapy, which not only preserves the appearance and function of breast, but also has the same efficacy as radical surgery, according to the data, the 20-year survival rates of radical surgery and breast-conserving surgery + radiotherapy are 70.9% and 71.2% respectively. 2.Palliative radiotherapy can be given to patients with advanced tumors or those who cannot receive surgery or chemotherapy for various reasons. The principle is to relieve patients’ pain and improve their quality of life without increasing their new pain. It has obvious therapeutic effect on patients with brain metastases and bone metastases. 3.Preoperative radiotherapy Preoperative radiotherapy can improve the resection rate of tumor, reduce the chance of intraoperative tumor implantation and postoperative recurrence rate, which is applicable to esophageal cancer, laryngeal cancer, maxillary sinus cancer, soft tissue sarcoma, rectal cancer, etc. 4.Postoperative radiotherapy For tumors with residual after resection, lymph node metastasis or subclinical lesions, postoperative radiotherapy can improve the local control rate of tumors. It can be used for various malignant tumors.