The most common method to treat brain tumors is craniotomy. However, patients not only have to suffer from great mental stress and pain caused by the treatment, but also have to face a series of risks such as possible death and disability after surgery, bleeding and infection. With the development of medical technology, people expect that minimally invasive treatment techniques can replace traditional craniotomy. But what else can be used to treat brain tumors without a scalpel? The concept of “stereotactic radiosurgery” was first introduced by Lars Leksell, a Swedish professor of neurosurgery, back in the 1950s. He wanted to use a stereotactic approach, using a narrow beam of cobalt 60 to cross-focus high-energy radiation on a limited target area in the skull to induce a radiobiological effect, in order to precisely destroy the diseased tissue in the brain. The normal tissues around the target area are minimally damaged by the sharply reduced irradiation dose, thus forming a “knife-like” therapeutic boundary at the edge of the target area and achieving a surgical resection-like effect. Therefore, the treatment device is imaginatively called “gamma knife”. The radiation is focused on the center of the target lesion, producing radiation damage and causing tissue necrosis by virtue of the high energy. In the periphery of the target area, the radiation causes the DNA strands of the tumor cell nucleus to break or unwind, losing the ability to repair and replicate, and causing the tumor cells to lose their ability to reproduce, thus achieving the purpose of controlling tumor growth. Tumor cells are disintegrated and absorbed after the end of cell cycle. The length of the entire process can be as short as 1 to 3 months or as long as 2 to 3 years, depending on the radiosensitivity of the focal tissue. After more than ten years of development, Leksell and colleagues applied the first gamma knife to clinical treatment in 1967. And in 1972, the cobalt source was increased to 179, and the second generation of gamma knife was designed. In 1987, the third generation of U-type and B-type gamma knives were introduced one after another, and the number of cobalt sources increased to 201, and the mechanical accuracy was greatly improved. With the development of computer technology, gamma knife dose planning, also from manual computing, improved to a workstation that can be three-dimensional design. This has greatly improved the accuracy of treatment. As of December 2001, 156 Leksell Gamma Knives in China, Japan, the Middle East, South and Southeast Asia, as well as in Europe, the United States and South America, have treated more than 180,000 patients with various types of brain tumors, cerebrovascular disease and functional disorders. In various international medical journals related to medical papers nearly 10,000 pieces of articles. It is the only gamma knife certified by the U.S. FDA and relevant European agencies to enter clinical treatment. The effectiveness of stereotactic radiosurgery represented by it in the treatment of brain tumors has also been confirmed by international colleagues. At present, the number of people treated with Gamma Knife in the world is about 25,000 annually. Gamma Knife is suitable for the treatment of brain tumors and functional disorders with an average lesion diameter of less than 3 cm. Indications for gamma knife treatment include: cerebrovascular malformations, functional neurosurgical diseases, intracranial tumors and some extracranial tumors. Benign intracranial tumors include: meningioma, pituitary tumor, craniopharyngioma, nerve sheath tumor (auditory neuroma, trigeminal nerve sheath tumor), pineal tumor, hemangioblastoma, etc.; malignant intracranial tumors include: glioma, metastatic tumor, malignant lymphoma, germ cell tumor, jugular venous bullae tumor, chordoma, etc.; vascular lesions refer to: cerebral arteriovenous vascular malformation, cavernous hemangioma; extracranial tumors: nasopharyngeal carcinoma recurring after radiotherapy Extra-cranial tumors: nasopharyngeal carcinoma recurring after radiotherapy, nasopharyngeal fibrovascular tumor, intraocular tumor, etc. Functional neurosurgical diseases such as: trigeminal neuralgia, Parkinson’s disease, torsion spasm, secondary epilepsy, etc. For patients with residual or recurrent brain tumors after surgery and whose physical condition cannot tolerate craniotomy, gamma knife treatment can be chosen. Gamma knife treatment is highly precise, safe and reliable. Especially for lesions deep in the brain or important functional areas, Gamma Knife is basically harmless to the normal brain tissue around the lesion, and the complications after treatment are greatly reduced. Treatment is time-saving and simple, patients only need to do the necessary physical examination and examination before treatment. No need to shave the head, no significant pain. The treatment only needs to be done once, and the whole treatment course usually takes only 1 ~ 2 hours. The patient can be discharged the same day or the next day after treatment, which does not affect the patient’s daily life, work and study. It also reduces the trouble of accompanying family members. In 1993, Huashan Hospital affiliated to Fudan University and the American International Medical Group cooperated and took the lead in introducing the B-type Gamma Knife in China and established the Shanghai Gamma Knife Hospital. With the assistance of the Department of Neurosurgery and Radiology of Huashan Hospital, the hospital has so far treated more than 8,200 patients with brain tumors and cerebrovascular malformations with the Gamma Knife. The number of patients treated accounts for one twentieth of the number of patients worldwide in the same period, the largest number of patients treated by a single Gamma Knife internationally. Patients from all over the motherland and Hong Kong and Macao, and patients from Southeast Asia, the Netherlands, Germany, Russia and other countries also came to the hospital to receive gamma knife treatment. All have achieved good results. In the treatment of pituitary microadenoma, auditory neuroma, cerebrovascular malformation, brain metastases and functional diseases, it is the leading level in China. The research results were awarded the third prize of Shanghai Science and Technology Progress. He has also published several articles in the Journal of Neurosurgery>, an internationally renowned authoritative journal of neurosurgery, and his medical research achievements have been noted by international colleagues. And received from Jilin, Changsha, Guangzhou, Shijiazhuang and many other domestic gamma knife center for further training, and become the leading domestic gamma knife treatment outstanding medical education and research comprehensive training base. At the end of 2000, the fourth generation of highly intelligent C-type Gamma Knife entered clinical treatment. Based on the original B-type Gamma Knife, the automatic positioning system and automatic coordinate detection system have been introduced to eliminate the error of manual operation and make the treatment accuracy reach +0.1mm. and shorten the operation and treatment time, making the treatment more safe, effective and convenient. The accompanying GammaPlan workstation adopts the most advanced automatic inverse fit design treatment planning system, and the means to optimize the feasibility detection of program selection, combined with the network. C-type Gamma knife is described as the “fine art” of radiosurgery. In August 2002, the Shanghai Gamma Knife Hospital introduced the highly intelligent C-type Gamma Knife. The device on the basis of the original C-type made some technical improvements, more humane and safe, thus more strongly ensure the efficacy of treatment. At present, the device has treated nearly 200 cases of encephalopathy patients and is increasingly showing her technological content. It provides the patients with a real safe and effective surgical treatment method that can treat brain tumor as well as without craniotomy.