What is a gamma knife? Advantages and disadvantages of gamma knife

"Gamma knife" is called "knife", but it is not a real scalpel. It is a hemispherical helmet covered with a collimator, which can emit 20 1 high dose ion rays of cobalt 60-γ rays. We call it a "target" to locate a certain part accurately through modern imaging technologies such as CT and magnetic vibration. Its positioning is extremely accurate, and the error is often less than 0.5 mm; The dose gradient of each gamma ray is very large, and there is almost no damage to the tissue. However, 20 1 rays collected from different positions can fatally destroy the target tissue. It is named after its scalpel function. It has the advantages of no trauma, no general anesthesia, no surgery, no bleeding and no infection. Second, the principle of gamma knife treatment The gamma knife stereotactic radiotherapy system is a stereotactic radiosurgery treatment device that integrates stereotactic technology and radiosurgery technology and mainly treats brain diseases. It adopts the geometric focusing method of gamma rays, and focuses the planned dose of gamma rays on the pre-selected target in the body through accurate stereo orientation, so as to destroy the tissues in the point once and fatally, and achieve the effect of surgical resection or destruction. The normal tissue around the focus is out of focus and only irradiated by a single beam of gamma rays, so the energy is very low and it is not damaged. Just like focusing sunlight with a magnifying glass, the focused heat can ignite an object, while the sunlight outside the focus is safe. Using gamma rays instead of scalpels, the therapeutic irradiation range is very clear from normal tissues, and the edge is like a knife, so people call it "gamma knife" vividly. Gamma knife is divided into head gamma knife and body gamma knife. Head gamma knife includes static gamma knife and rotary gamma knife. Static gamma knife is to install multiple cobalt sources in a spherical helmet and focus on a certain point of the skull. Rotary gamma knife is improved on the basis of static gamma knife and has many advantages. This is a patent of China. Head gamma knife can cure trigeminal neuralgia (trigeminal neuralgia), glioma, meningioma, acoustic neuroma, pituitary adenoma, craniopharyngioma and so on. Body gamma knife is mainly used to treat all kinds of tumors in the whole body. 1 and intracranial benign tumors such as acoustic neuroma, pituitary adenoma and meningioma below 30 mm; 2. Small and deep intracranial arteriovenous malformation; 3. Some operations cannot remove clean benign and malignant tumors; 4. Small and well-defined intracranial metastatic carcinoma; 5, Parkinson's disease, epilepsy, mental illness and other functional diseases. 1. Routine examination after admission: general physical examination, chest X-ray, electrocardiogram, blood test, etc. 2. Imaging examination: High-speed spiral CT and/or magnetic resonance can exclude intracranial tumors, cerebrovascular diseases and other space-occupying lesions, providing a basis for 3D image fusion. 3. EEG: including 32-lead/16-lead general EEG, 24-hour EEG and remote 128-lead full digital EEG monitoring. 4. Further select the items to be examined when necessary: magnetoencephalography, functional magnetic vibration, spectrum analysis of magnetic vibration, single photon emission computed tomography, positron emission computed tomography. The controllable gamma rays emitted by the gamma knife of radioactive element "Cobalt -60" are focused on the tumor focus after geometric focusing, which fatally damages the tumor tissue in the target area and achieves the same effect as a scalpel. Gamma knife is the perfection and development of scalpel in tumor treatment, but it can't replace scalpel. Gamma knife is a radiation-induced lethal therapy, which is incomplete and far less effective than surgery in the long run, so it is suitable for advanced tumors. Or surgical contraindications; Or lose the opportunity for surgery; Or have serious complications; Or postoperative recurrence and metastasis. The scalpel can completely remove the tumor under direct vision and is the first choice for early tumor treatment. Gamma knife is a bloodless operation without anesthesia and special preparation. On the surface, it seems to be a non-invasive treatment, but in fact, the potential trauma of gamma knife should not be underestimated. Gamma knife is a radiation killing therapy. All normal tissues and tumor tissues in the irradiated area were killed without error. The larger the irradiation range and the longer the irradiation time, the greater the damage to normal tissues, especially to living organs. Gamma knife will also cause a series of radiation reactions during or after irradiation, such as hair loss, nausea and vomiting, fatigue, leukopenia, thrombocytopenia and even pancytopenia, and even radiation sickness that is difficult to treat in severe cases; Gamma rays can also interfere with and destroy the normal immune function of human body, which is undoubtedly worse for cancer patients. Some tumors disappear quickly after gamma knife treatment. However, it lasted for a short time, recurred after a few months, deteriorated rapidly and died, which may be related to low immune function.