目的 探讨注射用培美曲塞二钠联合伽马刀治疗非小细胞肺癌脑转移瘤的临床疗效。方法 选取2012年1月-2016年1月徐州矿务集团总医院收治的非小细胞肺癌的脑转移瘤患者90例，将全部患者随机分为对照组和治疗组，每组各45例。对照组采用伽马刀进行治疗，剂量是40%~60%等剂量线12~13 Gy，依据瘤体大小分1~2次做完，间隔3~5 d。治疗组在对照组的基础上静脉滴注注射用培美曲塞二钠，500 mg/m²（溶于生理盐水），1次/21 d，治疗3次。观察两组的临床疗效，比较两组的血清中肿瘤标志物癌胚抗原（CEA）、细胞角质素片段抗原21-1（CYFRA21-1）水平。结果 治疗后，对照组和治疗组的有效率分别为64.44%、84.44%，肿瘤局部控制率分别为77.78%、93.33%，两组比较差异有统计学意义（P<0.05）。治疗后，两组CEA、CYFRA21-1水平均显著下降，同组治疗前后比较差异有统计学意义（P<0.05）；且治疗组这些观察指标明显低于对照组，两组比较差异具有统计学意义（P<0.05）。结论 注射用培美曲塞二钠联合伽马刀治疗非小细胞肺癌脑转移瘤具有较好的临床疗效，可降低CEA、CYFRA21-1水平，安全性较好，具有一定的临床推广应用价值。

Objective To investigate the clinical effect of Pemetrexed Disodium for injection combined with gamma knife in treatment of brain metastasis of non small cell lung cancer. Methods Patients (90 cases) with brain metastasis of non small cell lung cancer in General Hospital of Xuzhou Mineral Group Company from January 2012 to January 2016 were randomly divided into control and treatment groups, and each group had 45 cases. Patients in the control group were given gamma knife treatment. The doses ranged from 40% to 60%, and the dose line was set 12-13 Gy. Patients were treated for 1-2 times according to the size of the tumor with an interval of 3-5 d. Patients in the treatment group were iv administered with Pemetrexed Disodium for injection on the basis of the control group, 500 mg/m² (soluble in normal saline), once every 21 days, treated for 3 times. After treatment, the clinical efficacies were evaluated, and the levels of CEA and CYFRA21-1 in two groups were compared. Results After treatment, the clinical efficacies in the control and treatment groups were 64.44% and 84.44%, respectively, and the local tumor control rates in the control and treatment groups were 77.78% and 93.33%, respectively, and there was difference between two groups (P<0.05). After treatment, the levels of CEA and CYFRA21-1 in two groups were significantly decreased, and the difference was statistically significant in the same group (P<0.05). And the observational indexes in the treatment group were significantly lower than those in the control group, with significant difference between two groups (P<0.05). Conclusion Pemetrexed Disodium for injection combined with gamma knife has clinical curative effect in treatment of brain metastasis of non small cell lung cancer, and can decrease CEA and CYFRA21-1 levels, with good safety and a certain clinical application value.