Gamma Knife treatment principle The 30 sources (or 18 sources), 8500ci (or 6000ci) of energy are focused on a single point by means of spiral focusing. During treatment, the 30 beams (or 18 beams) are rotated and focused toward the focal point so that each beam becomes a dynamic cone scanning surface with the focal point being the apex of the cone. The lesion at the focal point is irradiated with a continuous high dose, while the surrounding tissues are irradiated with a scanning low dose, thus widening the dose gradient between tumor tissue and normal tissue, making it possible to effectively kill the tumor and reduce surrounding tissue damage. Indications and contraindications of body gamma knife I. Indications (radical treatment of small tumors, additional treatment after general radiotherapy, retreatment of recurrence after radiotherapy) 1. limited lesions, radical treatment of small tumors; 2. old and weak who cannot tolerate enough surgery, radiotherapy or chemotherapy, unwilling to operate; 3. postoperative residual, recurrence or recurrence after radiotherapy; (1) lung cancer, metastatic lung cancer (2) liver cancer, metastatic liver (3) gallbladder cancer, bile duct cancer (4) pancreatic cancer (5) mediastinal tumor (6) adrenal tumor (7) kidney cancer (8) retroperitoneal tumor (9) postoperative pelvic recurrence of rectal cancer (10) metastasis of lymph nodes in the chest, abdomen and pelvis, etc. (11) vertebral metastasis and bone metastasis (12) postoperative recurrence and metastasis of esophageal cancer, gastric cancer, colorectal cancer, bladder cancer (13) prostate cancer Contraindications: gastric cancer, colorectal cancer rectal cancer (except for local recurrence of rectal cancer after surgery), massive pleural fluid, cachexia, complicated by serious infection, etc. Indications and contraindications for head gamma knife I. Indications: 1) intracranial occupying lesions <3.5 cm; 2) intracranial lesions that cannot be removed by surgery or cannot tolerate surgery; 3) residual after surgery or recurrence after surgery or radiotherapy; (1) cerebrovascular malformations: AVM (arteriovenous malformation), AOVM (cavernous hemangioma) (2) benign tumors: pituitary tumor, auditory neuroma, meningioma, craniopharyngeal (3) Malignant tumors: brain metastases, glioma, melanoma, chordoma, pineal tumor, nasopharyngeal carcinoma; (4) Functional diseases: trigeminal neuralgia, intractable epilepsy, intractable headache, some refractory neuropathies. (2) Contraindications: intracranial hypertension (without treatment), oversized lesions, diffuse lesions. The advantages of head gamma knife and body gamma knife Head gamma knife and body gamma knife treatment, are precise radiotherapy treatment, with "high precision, high dose, high efficacy, low damage" characteristics. The efficacy is precise, reliable, no incision, no bleeding, no pain, small trauma, safe, simple, time-saving treatment only 10-30 minutes per treatment (head gamma knife for single treatment, body gamma knife for split treatment), a simultaneous treatment of multiple lesions, no general anesthesia, bleeding, the risk of infection, relatively low requirements for the physical condition of patients, some elderly, frail, can not tolerate surgical patients also Gamma knife treatment can be performed. Some patients can be treated on an outpatient basis.