Gamma knife treatment of pituitary tumor patients, because compared to surgery or other treatment modalities, the harm is minimal, equivalent to a safe non-invasive and effective treatment modality. Some patients because of tumor compression, pituitary tumor patients themselves have tumor compression of the normal pituitary gland, the normal pituitary function is generally damaged, so the pituitary function is not normal, plus some patients have surgery, surgical trauma or after the gamma knife, radiation on the normal pituitary gland also has a certain degree of radioactive damage, resulting in a certain decline in the patient’s pituitary function. So the patient’s harm is mainly caused by the pituitary gland function after the endocrine disorder, but these patients can be treated by endocrine therapy, such as deficiency of which hormone must be treated with that hormone replacement, the effect is still very sure. The other less common harm is the damage to the optic nerve and optic pathway caused by radiation, because the pituitary gland is above the optic nerve and optic cross, treatment with gamma knife because after all is radiation, for the tumor cells caused by the killing effect, for the normal nerve will also have a certain irradiation, so some patients may appear after treatment damage to the optic nerve, resulting in vision loss, visual field loss.