Treatment of Low Locally Advanced Rectal Cancer With Radiotherapy Removal TNT Plus Neoadjuvant Therapy

Inclusion Criteria: * Aged between 18 and 70; * Histologically confirmed adenocarcinoma of rectum; * The distance from the lower edge of the tumor to the anus is ≤ 10cm; * ECOG score ≤ 1; * Have not received any anti-tumor treatment before; * Preoperative abdominal enhanced CT or MRI showed cT4, cN0-2; M0 chest and abdomen CT showed no obvious metastasis. (Note: PET-CT is recommended when small nodules can not be identified by liver or lung CT, and can still be included in the group when considering the possibility of metastasis) * Hematological indicators and liver and kidney function within 7 days are within the normal range; * Sign the informed consent form and be able to follow the research and /or follow-up procedures. Exclusion Criteria: * Have serious basic diseases, such as heart disease, renal failure, severe liver failure or liver failure, coagulation dysfunction, etc; Postoperative recurrence of colorectal cancer; * The patient had a history of malignant tumor within 5 years; * Pregnant or lactating women; * The patient has a history of adjuvant radiotherapy for other system diseases, and surgical contraindications, so it is not suitable for surgery; * The patient has had radiotherapy and chemotherapy records before this visit; * Distant metastasis was found during operation; * Patients with poor radiotherapy compliance and difficult cooperation;