1, clear tumor primary or metastasis, as far as possible with a level I diagnosis (pathology, histology, cytology); 2, require recent imaging data; 3, actual measurement of tumor activity at the time of treatment; 4, CT machine positioning accuracy assurance: fasting, enhancement, oral or infusion of contrast media, as appropriate, at the time of positioning; 5, limit tumor activity at the time of positioning and treatment, as far as possible to ensure its consistency; 6, positioning Mark the body projection of the tumor and the distance from the center of the tumor to the body surface; 7. Regular whole-body gamma knife accuracy radiation dosimetry detection system; 8. Maintain the same conditions as when positioning at each irradiation; 9. Implement a double inspection and supervision system for the whole process of positioning and treatment; 10. Regular review, follow-up, data analysis, efficacy assessment and experience summary.