Gamma knife, also known as stereotactic gamma radiation therapy system, is a modern computer technology, stereotactic technology and surgical technology in one of the therapeutic equipment, it will be cobalt-60 issued by the geometric focus of gamma rays, concentrated on the lesion, one-time, lethal destruction of the target tissue, and the rays through the body’s normal tissue almost no harm, and the dose is sharply reduced, so its treatment irradiation range and The treatment irradiation range and the normal tissue boundary is very obvious, the edge of the same as a knife cut, people imaginatively called “gamma knife”. ”Gamma knife” named “knife”, but in fact is not a real scalpel, it is a hemispherical helmet covered with direct aligner, the helmet can shoot 201 cobalt 60 high-dose ion rays – gamma rays. It is precisely located in a certain area through modern imaging technology such as CT and MRI, which we call “target point”. Its positioning is extremely accurate, and the error is often less than 0.5 mm; the dose gradient of each gamma ray is so great that there is almost no damage to the tissue. But 201 rays from different locations together can be lethal * to destroy the target tissue. It is named because it functions like a scalpel, and has the advantages of no trauma, no need for general anesthesia, no incision, no bleeding and no infection. Gamma knife is divided into head gamma knife and body gamma knife. The head gamma knife is a multiple cobalt source installed in a spherical helmet, so that it is focused on a point in the skull, forming a narrow beam of sharp-edged gamma rays. During treatment, the narrow beam of rays is converged on the lesion to form a limited high-dose area to destroy the lesion, mainly used for the treatment of small intracranial tumors and functional diseases. The body gamma knife is mainly used to treat various tumors throughout the body. Gamma knife is divided into head gamma knife and body gamma knife. The head gamma knife has static gamma knife and rotating gamma knife, static gamma knife is a number of cobalt sources installed in a spherical helmet to focus on a point in the skull, rotating gamma knife is improved on the basis of the static type, with many advantages, is patented in China. Currently, the Leksell Gamma Knife is commonly used internationally, which is the standard equipment for stereotactic radiosurgery. Since the body gamma knife is not recognized by the Chinese Ministry of Health, it is currently only used in the non-Ministry of Health managed hospital system in mainland China. The body gamma knife is mainly used to treat various tumors throughout the body. Head Gamma Knife clinical indications: 1, 30 mm or less of auditory neuroma, pituitary tumor, meningioma, pineal tumor, lymphoma and other intracranial tumors; 2, intracranial arteriovenous malformations; 3, cavernous hemangioma; 4, some surgery can not remove clean benign tumors; 5, smaller and clear edge of the intracranial metastatic cancer; 6, functional neurosurgery diseases: primary or drug treatment is ineffective trigeminal neuralgia, Intractable pain, movement disorders caused by Parkinson’s disease, epilepsy and other functional diseases; 7. Spinal cord tumors of cervical segment 7 and above; 8. Some extracranial tumors of head and neck.