脑转移瘤50％～50％来自肺癌，多见干肺小细胞癌和肺腺癌。其临床特点是起病急，发展快、病程短、一般状态差［1,2］。对这类患者临床上有用预防性头颅放疗或药物的化学预防。本文就1994～1996年经过环巴亚硝脲（CCNU）预防原发性肺癌脑转移的观察结果作一介绍。1临床资料43例 Metastatic brain tumors from 50% to 50% from lung cancer, more common in small cell lung cancer and lung adenocarcinoma. Its clinical features are acute onset, rapid development, short duration, and poor general state [1,2]. Clinical prevention of prophylactic cranial radiotherapy or drug chemoprevention is clinically useful for these patients. In this paper, the results of the observation of the prevention of primary lung cancer brain metastases by CCNU from 1994 to 1996 are introduced. 1 Clinical data 43 cases