RESUMEN
Objective To evaluate the clinical toxicity and efficacy of S-1 combined with γ-ray body stereotactic radiation therapy in treatment of locally advanced pancreatic cancer.Methods Forty-five patients with locally advanced pancreatic cancer were randomly divided into two groups.The combination group received γ-ray stereotactic body radiation therapy which was given isodose curve of 50 ％-60 ％,tumor encircling dose of 3.0-4.5 Gy per fraction depended on dimension of tumors,9-12 fractions.Combined with S-1 40 mg/m2,2 times/d,for consecutive twenty-one days for four courses.The control group was given γ-ray stereotactic body radiation therapy only.Toxicities and effects were evaluated according to the criteria of WHO and RTOG.Results The CR rates in combination group and control group were 30.4 ％ (7/23) and 13.6 ％ (3/22),the response rates were 91.3 ％ (21/23) and 63.6 ％ (14/22) (x2 =4.980,P =0.026).The rates of gastrointestinal tract side reaction in combination group and control group were 82.6 ％ and 68.2 ％ (x2 =1.267,P =0.260),myelosuppression in combination group and control group were 78.3 ％ and 63.6 ％ (x2 =1.171,P =0.279).The rate of Ⅲ-Ⅳ grade myelosuppression in combination group were higher than that in control group (x2 =4.874,P =0.027).The median progression-free survival (PFS) rates of two groups were 8 months and 6 months respectively (x2 =1.357,P ＞ 0.05),the median survival period were 17 months and 14 months (x2 =1.017,P ＞ 0.05),1 year survival rates were 60.9 ％ and 54.5 ％ respectively (x2 =0.184,P ＞ 0.05).Conclusions S-1 combined with body gamma system treatment can improve local control rate and effective rate for inoperable patients with local advanced pancreatic carcinoma,and the adverse reactions are well tolerated.This method can be used as locally advanced pancreatic cancer chemoradiation safe and effective choice.