The purpose of this study is to evaluate the effect of intrarectal Amifostine administration on acute radiation-induced rectal toxicity in pre-operative chemo-radiotherapy.

To evaluate the different use way of intrarectal Amifostine administration on acute radiation-induced rectal toxicity in pre-operative chemo-radiotherapy.

Inclusion Criteria:

• pathologically confirmed rectal cancer, preoperative stage II / III (T3-4N0 or T1-4N + M0).
• tumor distance from anus less than 12 cm.
• KPS score not less than 70
• can be tolerated chemotherapy and radiotherapy.
• pelvic who had no history of radiation therapy.
• Non-allergic history of fluorouracil or platinum-based chemotherapy drugs.
• blood pressure can be controlled by drugs in the normal range (90 ≤ systolic blood pressure ≤ 140,60 ≤ diastolic blood pressure ≤ 90).
• a full understanding of the study, the ability to complete all of the treatment plan, follow up the conditions and sign the informed consent.

Exclusion Criteria:

• other malignancy (past or at the same time), does not include curable non-melanoma skin cancer and cervical carcinoma in situ; does not include resectable primary colon cancer (synchronous or metachronous).
• pregnant or lactating patients.
• fertility but did not use contraceptive measures.
• existing active infection.
• merge serious complications, can not tolerate the treatment, such as 6 months of myocardial infarction, mental illness, uncontrollable diabetes or uncontrollable hypertension or hypotension.
• concurrent treatment with other anticancer drugs.
• can not complete treatment or follow-up.