Preoperative Chemoradiotherapy and Toripalimab in Locally Recurrent Rectal Cancer

Inclusion Criteria: 1. Patient is 18-75 years old at the time of signing the informed consent form. 2. ECOG performance status 0-1. 3. Pathological confirmed or MRI/ enhanced CT confirmed pelvic recurrence. 4. No distant metastasis lesions outside the pelvic. 5. No prior radiotherapy within 6 months. 6. Participants with pelvic recurrence who have not previously been treated with first-line chemotherapy. 7. Life expectancy at least 24 weeks. 8. Adequate organ function (bone marrow, liver, kidney and clotting function) within 7 days before the first administration without using blood products or hematopoietic stimulating factors. 9. Non pregnancy or lactation. 10. Fully informed and willing to provide written informed consent for the trial. Exclusion Criteria: 1. Neutrophil \< 1.5×10\^9/L, PLT \< 75×10\^9/L. 2. TBIL \> 1.5 ULN. 3. AST or ALT \> 2.5 ULN, or ALT and / or AST \> 5 ULN in patients with liver metastasis. 4. Cr \> 1.5 ULN. 5. Serious electrolyte abnormalities. 6. Active coronary artery disease, severe/unstable angina, or newly diagnosed angina or myocardial infarction within 12 months. 7. Arterial thrombosis or deep vein thrombosis within 6 months, such as cerebrovascular accidents (including transient ischemic attacks), pulmonary embolism, deep vein thrombosis. 8. Congestive cardiac failure ≥ NYHA grade 2. 9. Human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS), untreated active hepatitis (hepatitis B defined as HBV-DNA ≥ 500 IU/ml; hepatitis C defined as HCV-RNA higher than lower limit of detection) or hepatitis B and hepatitis C virus co-infection. 10. Active inflammatory bowel disease or other colorectal diseases that lead to chronic diarrhea. 11. Suspected autoimmune disease. 12. Interstitial lung disease, non-infectious pneumonia or uncontrollable systemic diseases (such as diabetes, hypertension, pulmonary fibrosis and acute pneumonia). 13. Suspected allergic to any drugs used in the trial. 14. History of any immune checkpoint inhibitor therapy. 15. Clinically detectable second primary malignancy, or history of other malignancies within 5 years. 16. Pregnant or lactating women or women who may be pregnant have a positive pregnancy test before the first medication; Or the female participants themselves and their partners who were unwilling to implement strict contraception during the study period. 17. The investigator considers that the subject is not suitable to participate in this clinical study due to any clinical or laboratory abnormalities or compliance problems. 18. Serious mental abnormalities.