Intraoperative radiation therapy for patients with mid- to late-stage malignant tumors and recurrence of head and neck The incidence of malignant tumors is increasing year by year, and hospitals admit especially many patients with malignant tumors every year, and the same is true for head and neck malignant tumors, such as oral cancer, parotid malignant tumors, metastatic lymph node cancer of the neck, malignant lymphoma, etc., which directly affect the 3-year survival rate of patients, and it is also very difficult for some recurrent cases of head and neck malignant tumors in clinical practice. How to prolong the survival rate of recurrent patients and patients with intermediate and advanced tumors is an urgent clinical problem to be solved. Spiral tomography radiotherapy machine, Mobetron intraoperative radiotherapy special gas pedal, performs all-round direct radiation therapy in the surgical field during surgery, the specific scheme is: 1. surgical enlargement to remove the tumor; 2. the sterile radiation head of Mobetron intraoperative radiotherapy special gas pedal immediately extends into the surgical field, irradiates the surgical field and surrounding target tissues, and irradiates different doses for different nature of tumors. This prevents radiation from damaging other tissues (e.g. skin, mucosa, bone) in large quantities; 3. Then radioactive particles are implanted around the surgical field for continuous radiation therapy; 4. Finally, the wound is sutured. In this way, for individual recurrent tumors that cannot be completely removed cleanly, the tumor cells can also be killed, prolonging the survival period and improving the quality of life of patients. For a few patients with recurrence who have lost the time of surgery, take the implantation of radiation particles under CT navigation, which can reach inside the tumor lesion through skin puncture under the guidance of CT three-dimensional image, and repeatedly implant the radiation particles, and then around the tumor lesion, implant a large number of radiation particles in a fan shape. The CT navigation system enables the surgeon, through the high-resolution display, to observe the current surgical access from all directions, as well as The CT navigation system enables the surgeon to observe the current surgical approach and various parameters (angle, depth, etc.) from all directions through the high-resolution display, so as to avoid the danger zone to the maximum extent and reach the target lesion in the shortest time, which greatly reduces the amount of blood loss, surgical trauma and complications of the patient, and makes the surgery tend to be minimally invasive. The operation time of each case is about 1 hour, the bleeding volume does not exceed 30ml, and the patient can move around and drink water on the same day after the operation.