Gamma Knife is an important treatment for cavernous hemangiomas of the brain. It is usually safer, but side effects such as hair loss, immune deficiency, vision loss, and cerebral edema may occur. 1. Hair loss: Although Gamma Knife is a minimally invasive treatment, it may cause damage to the scalp, resulting in hair loss. 2. Loss of immunity: Gamma Knife may damage the immune system of the human body, resulting in the lowering of white blood cells, thus affecting the immune function of the human body. 3. Loss of vision: Gamma Knife may damage the optic nerve during the procedure, resulting in side effects such as loss of vision. 4. Cerebral edema: Gamma Knife may damage the normal brain tissue of the brain during the surgery, resulting in cerebral edema. Patients who experience any discomfort after Gamma Knife surgery are advised to go to the hospital in time.