目的:评估单独采用X刀放射外科治疗多发脑转移瘤的疗效及其影响因素。方法:133例多发脑转移瘤病人单独接受X刀放射外科治疗,不合并全脑放射治疗。原发恶性肿瘤包括非小细胞肺癌、乳腺癌及其它。平均脑转移瘤的个数为4.4个(2～12个),平均肿瘤总体积为16.2cm3(1.0cm3～53.0cm3),平均边缘剂量为16.7Gy,平均随访时间7.0月。结果:中位生存时间为9.0月。COX回归分析发现:肿瘤总体积、PRA等级、边缘剂量为显著预后因子;脑转移瘤的个数、年龄、中心剂量没有统计显著性。结论:肿瘤总体积、RPA等级为多发颅内转移瘤显著预后因子。肿瘤总体积应该作为放射外科的选择标准,而不是转移瘤的个数。多发脑转移瘤单独采用X刀放射外科治疗可以获得满意的疗效,而是否有必要全脑放射治疗,值得商榷。 PURPOSE: To evaluate the efficacy and influencing factors of X-knife radiosurgery in the treatment of multiple brain metastases. Methods: 133 patients with multiple brain metastases underwent X-knife radiosurgery alone without brain radiation therapy. Primary malignancies include non-small cell lung cancer, breast cancer and others. The average number of brain metastases was 4.4 (2 ~ 12). The average tumor volume was 16.2 cm 3 (1.0 cm 3 ~ 53.0 cm 3). The average marginal dose was 16.7 Gy with an average follow-up time of 7.0 months. Results: The median survival time was 9.0 months. COX regression analysis showed that the total tumor volume, PRA grade and marginal dose were significant prognostic factors. There was no statistical significance in the number, age and central dose of brain metastases. Conclusion: The total tumor volume and RPA grade are significant prognostic factors for multiple intracranial metastases. The total tumor volume should be used as a radiosurgery selection criteria, rather than the number of metastases. Multiple brain metastases alone with X knife radiosurgery can obtain satisfactory results, and whether it is necessary for whole brain radiation therapy, is debatable.