When it comes to the treatment of tumor, the first thing that comes to mind is surgery, and even think that if you cannot operate, you lose all the chances! Unbeknownst to us, with the rapid development of medical imaging technology, stereoscopic positioning technology, computer technology, radiotherapy equipment and technology, modern radiotherapy has entered the era of precise treatment of tumors with three-dimensional irradiation, and has become the preferred means of local radical treatment for most tumors. Using modern radiotherapy technology to treat tumors can achieve correct and timely detection of the target, accurate strike on the target, complete destruction of the target, and minimize the risk of radiation damage. According to statistics, the 5-year survival rate of nasopharyngeal carcinoma stage I-IV treated with intensity-modulated radiotherapy in modern radiotherapy technology is about 75%, and the 5-year survival rate of early-stage nasopharyngeal carcinoma treated with intensity-modulated radiotherapy technology is over 90%; the 5-year survival rate of stage I non-small cell lung cancer treated with body stereotactic radiotherapy technology in modern radiotherapy technology is 70%; the whole-body gamma knife is used by our department to treat early-stage non-small cell lung cancer that cannot be operated due to internal diseases or age. The 3-year survival rate of early stage non-small cell lung cancer treated by our department with whole body gamma knife is 78%, which not only avoids the risk of surgery, but also achieves the same effect of surgery with minimal side effects. In addition, modern radiotherapy techniques are used to treat liver cancer, pancreatic cancer, lung metastases, liver metastases and retroperitoneal tumors with remarkable efficacy. Therefore, for the treatment of parenchymal organ-confined tumors, “what surgery cannot do, modern radiotherapy can do; what surgery can do, modern radiotherapy can do better, with less trauma and higher quality of life!” Radiotherapy principle Radiotherapy is to destroy tumor cells by ionizing radiation, the goal is to make tumor receive high dose and normal tissues receive low dose, through high radiation dose to kill tumor cells or tumor-related tissues to control tumor growth, while minimizing radiation side effects to normal tissues around tumor. Radiation therapy was born for the treatment of tumors and has been developed for more than 100 years. It can be broadly divided into three stages: primary radiotherapy, conventional radiotherapy and modern radiotherapy. Before the 1950s, it was the era of primary radiotherapy; during the 50 years from the 1950s to the end of the last century, it was the era of conventional radiotherapy; in the 21st century, it has entered the era of modern radiotherapy. Modern radiotherapy is the combination of a series of new technologies such as stereotactic technology, imaging technology, computer technology, radiotherapy equipment and technology: CT/MRI positioning system and PET/CT positioning system can detect tumors early and correctly; image-guided radiotherapy system, spiral tomography radiotherapy system and head and body gamma knives and other equipment can strike the target precisely; enable the implementation of new modes of high-dose and short-course treatment The proposed and application of new strategies such as selective radiotherapy or local targeted removal of systemic lesions by local means, decapitation plus systemic drug-targeted therapy or chemotherapy integrated treatment mode have enabled radiotherapy to strike the target correctly, precisely and in sufficient quantity, and to achieve effects equivalent to or even better than surgical resection and less traumatic for some early-stage tumors. Modern radiotherapy mainly includes intensity modulated radiotherapy, stereotactic radiotherapy, three-dimensional conformal radiotherapy, etc. Gamma knife is one kind of stereotactic radiotherapy. Advantages of modern radiotherapy Modern radiotherapy has four main advantages over surgery: First, radiotherapy is less restricted by blood vessels, because blood vessels have higher tolerance to radiation, and it is safer to use radiotherapy when tumor infiltrates blood vessels and surgery is difficult. Secondly, there is no site restriction, radiation is pervasive, radiotherapy can be used in any site, especially in those sites where surgical exposure is difficult or important functional areas or tumor invasion cannot be removed, radiotherapy can be used, and the chance of radical treatment can be obtained for small early lesions. Thirdly, radiotherapy is non-invasive and has little effect on the whole body, and most patients with poor physical condition can tolerate radiotherapy. Fourthly, it can treat multiple lesions in the whole body, such as brain metastasis of lung cancer, which can be treated with radiotherapy for brain metastasis at the same time as radiotherapy for the primary lung lesion, which is the concept of whole body treatment by local means. Modern radiotherapy adaptive population With the progress of modern radiotherapy technology, more and more tumors preferred to modern radiotherapy can obtain high local control rate and survival rate, and patients have higher quality of survival after treatment. Various primary and metastatic parenchymal organ tumors, including lung cancer, liver cancer, pancreatic cancer, nasopharyngeal cancer, intracranial tumors, head and neck tumors, malignant lymphoma, penile cancer, prostate cancer, cervical cancer, esophageal cancer, thymoma, rectal cancer, breast cancer, bladder cancer, bone metastasis caused by various tumors, superior vena cava compression syndrome, etc. all belong to the treatment scope of radiotherapy.