立体定向放射外科(X刀)是颅脑肿瘤放射外科治疗的一种手段。X刀等中心的精度直接影响病人的治疗效果,X刀治疗时要求等中心的误差在1mm以内,每例病人治疗前都要进行验证。等中心校验和调整是X刀治疗质量保证工作的一项重要内容。等中心是机架旋转轴、治疗床旋转轴和准直器旋转轴 Stereotactic radiosurgery (X knife) is a means of radiosurgery treatment of brain tumors. X knife and other centers directly affect the accuracy of the patient’s treatment, X knife treatment center when the error is less than 1mm, each patient must be verified before treatment. Center calibration and adjustment is X knife treatment quality assurance an important part of the work. The isocenter is a rack rotation axis, a treatment bed rotation axis and a collimator rotation axis