Abstract: Objective To evaluate the efficacy of stereotactic body radiotherapy combined with coinstantaneous gemcitabine, and  gemcitabine alone for advanced pancreatic cancer.  Methods 56 advanced pancreatic cancer patients were assigned into observation group, which accepted stereotactic body radiotherapy combined with coinstantaneous gemcitabine 500 mg/m², d1,d8. Other 50 patients were assigned into the control group which only accepted  gemcitabine  1 000 mg/m², d1,d8,d15. Stereotactic body radiotherapy was delivered with a total dose of 4 0004 500 cGy in 10 fractions.  Results CT examinations were carried out 2 months after treatment. The response rate of the observation group and control group was 82% and 16% respectively, and the pain relief rate was 67% and 17% respectively. The time to progression of the observation group was 14 months, and was better than that of the control group（7.5 months,χ²= 7.31，P=0.032）.The median survival time of the observation group and control group was 15.8 months and 13.2 months, and the difference had no statistical significance(χ²= 3.28，P=0.082). Concolusion Stereotactic body radiotherapy combined with gemcitabine has a better overall response rate and a pain relief rate. It can prolong the time to progression, but can′t improve the overall survival.

Key words: Pancreatic neoplasms, Stereotaxic techniques, Drug therapy, combination