Objective:To evaluate the effect of gamma knife radiosurgery on primary hepatic carcinoma with portal vein tumor thrombosis(PVTT). Methods:Totally 64 unrecsectable patients with PVTT diagnosis by CT/MR scan were reviewed;28 patients did not receive any treatment and other 36 patients were treated with gamma knife stereotaxis radiation therapy. A total of 30-50 Gy dose was prescribed to 50%-70% isodose line and performed in 10 fractions of 3-5 Gy each time. The short-term herapeutic effects and survival time was observed. Results:In gamma knife treatment group

9 patients(25%) achieved complete response(CR)

14(38.9%)achieved partial response(PR)

6(16.7%)had stable disease(SD)and 7 patients(19.4%)had progressive disease(PD). The objective response rate(ORR)was 63.9%. The overall survival rates of 1 year and 2 years were 36.1% and 8.3% respectively

with a median survival time of 10 months. In non-treatment group

3 patients(10.7%)achieved a SD and 25(89.3%)achieved a PD. The 1 year and 2 years survival rates were 0

with a median survival time of 3 months. Conclusion:Gamma knife radiosurgery

which has mild adverse reaction and can prolong the survival time is a safe and effective method for primary hepatic carcinoma with portal vein tumor thrombosis.