Abstract: Objective Through the observation of result of conformal radiotherapy,to explore the clinical significance of three dimension conformal radiotherapy to treat the brain metastasis of lung cancer. Methods There have 35 case patients of lung cancer with brain metastasis,and 12 of them combined with extracranial metastasis, and the other 23 cases don't exist extracranial metastasis.All patients were treated by whole brain irradiation, 1.8 ~2 Gy/time for 5 times/week,and the total dosage was 30~40Gy.And then were...