Adjuvant IMRT With Concommitant Raltitrexed Chemotherapy for Locally Advanced Gastric Cancer After D0/D1 Radical Resection

Inclusion Criteria: 1. Informed consent signed.; 2. Age: 18-70 years old, sex is not restricted; 3. Pathologically diagnosed as gastric adenocarcinoma or gastroesophageal junction adenocarcinoma; did not receive neoadjuvant chemotherapy or radiotherapy before surgery;received the 2-3 cycles of chemotherapy of FOLFOX regimens or 1-2 cycles of XeLOX or SOX regimens after operation; 4. Received D0 or D1 operation, no tumor residual (R0); 5. Postoperative pathological stage of pT3N0, pT4N0 or any T, N1-2, without distant metastatic disease; 6. ECOG 0-2; 7. Normal blood analysis: WBC≥3.5 X 109/L, GRAN≥2.0 X 109/L = 2, Hb≥90g/L, PLT≥100 X 109/L; 8. Liver function: ALT or AST is less than or equal to 2.5 times of the normal high value (ULN); bilirubin is less than 1.5\*ULN, serum APK is less than 2.5 \* ULN; 9. Renal function: serum creatinine is less than 1.5 \* ULN, and creatinine clearance rate is more than 60ml/min; 10. No previous chemotherapy or radiation therapy history; 11. No organ transplant history; 12. Urine pregnancy test results are negative for women of childbearing age in the first 7 days and not in lactation before treatment; 13. Men and women of childbearing age agreed to adopt reliable methods of contraception for 30 days before , during and after the course of the study Exclusion Criteria: 1. Received D2 radical operation; 2. Tumor residual (R1/R2); 3. There was found evidence of distant metastasis (M1) or suspicious metastasis after examination; 4. Other cancer history, except skin basal cell carcinoma or cervix in-situ carcinoma; 5. Previously received chemotherapy or other systemic anticancer therapy, including cytotoxic drugs, targeted drugs; or had received abdominal radiotherapy; 6. Anticipate other clinical trials in four weeks before enrollment. 7. Severe complication, such as acute myocardial infarction in 6 months, uncontrolled diabetes, severe cardiac arrhythmia, etc. 8. Drug abuse history or alcohol addiction; 9. Active infection existed. 10. with severe malnutrition or severe anemia; 11. Human immunodeficiency virus (HIV) infection; 12. Pregnancy (confirmed by serum or urine beta -HCG test) or during lactation; 13. Can not tolerate this study or may be allergic to the drug used in this study; 14. Persons who have no or restricted capacity for civil conduct; or have mental illness, whom the researchers believe can not fully understand the possible complications of this study.