Abstract:ObjectiveTo investigate the better radiation modalities for single and multiple brain metastases. MethodsBetween July 2005 and July 2008, 50 patients with single or multiple brain metastases were retrospectively analyzed. The primary cancer of all patients were controlled. Thirty patients with whole brain radiotherapy and stereotactic radiosurgery were included in the combination group, and 20 patients with stereotactic radiosurgery were included in another group. Stereotactic radiosurgery prescription doses of 45%75% isodose line were used to wrap around the planning target, which was 1520 Gy in edge and 3045 Gy in center. Stereotactic radiosurgery was performed once. Whole brain radiotherapy total dose was 40 Gy, which was given to patients by 2 Gy in 1 fraction, 1 fraction every day, 5 times every week. ResultsThe efficient rate of combination group was 90% (27/30), and single group was 60% (12/20). It was obviously higher in combination group (χ2=6.294, P=0.012). For combination group, the 1year survival rate was 50% (15/30) and the 2year survival rate was 30% (9/30). However, for another group, the 1year survival rate was 35% (7/20) and the 2year survival rate was 15% (3/20). The survival rates of two groups were no difference (χ2=1.096, P=0.295; χ2=1.480, P=0.224). There were no patients survived more than 3 years in both groups. Stratified analyses showed that the 1year survival rates of the patients with single brain metastasis were no difference in two groups (100.0% vs 66.7%， χ2=1.556, P=0.212). Whereas the 1year survival rate in combination group of the patients with multiple brain metastases was higher than that in single group (42.3% vs 29.4%， χ2=11.023, P=0.001). There were no statistically significant differences in 2year survival rates in both groups with single and multiple brain metastases (75.0% vs 66.7%， χ2=1.200，P=0.273; 23.1% vs 5.9%， χ2=3.782，P=0.052). ConclusionWhole brain radiotherapy and stereotactic radiosurgery are important treatment modalities for single or multiple brain metastases. The optimal treatment modality for single brain metastasis is stereotactic radiosurgery, while it is a good choice to make whole brain radiotherapy and stereotactic radiosurgery for multiple brain metastases.

Key words:Radiosurgery,Radiotherapy,Brain metastases