A Multicenter, Phase 2 Study Evaluating the Value of Radiotherapy in Advanced Diffuse Large B-cell Lymphoma Patients With Extranodal Involvement and Large Tumors Undergoing Immunochemotherapy for PET-CT Assessment of Complete Remission

Inclusion Criteria:

1. Using the World Health Organization (WHO) classification of diseases, newly diagnosed diffuse large B-cell lymphoma with large masses (tumor diameter ≥ 7.5cm) and or extranodal involvement patients diagnosed by histology
2. Age: no limit, male or female;
3. ECOG score: 0-2
4. The laboratory meets the following requirements:

   4.1 The bone marrow hematopoietic function is basically normal: WBC ≥ 3.5×10\^9/L, ANC ≥ 1.0×10\^9/L, PLT ≥ 75 ×10\^9/L, Hb ≥ 80g/L;

   4.2 Liver function: AST/ALT≤2×ULN, TBILI≤2×ULN;

   4.3 Renal Function : creatinine clearance rate(Ccr) ≥50ml/min
5. Non-menopausal or non-surgical sterilization female patients of childbearing age must have a serum pregnancy test within 3 days before the first medication, and the result is negative; and they must be non-lactating. Female patients of childbearing age or male patients whose partners are women of childbearing age must agree to use highly effective methods of contraception during the study and within 6 months after the last administration of the study drug;
6. Expected survival period ≥ 6 months;
7. The patient voluntarily joined the study and signed the informed consent;

Exclusion Criteria:

1. Serum pregnancy test positive or breastfeeding women;
2. Lymphoma patients with central nervous system (CNS) invasion;
3. Clinically significant heart disease, including unstable angina, acute myocardial infarction 6 months before randomization, congestive heart failure (NYHA), cardiac function class III or IV; or cardiac left ventricular ejection fraction \<50%;
4. Patients with ≥2 grade neuropathy;
5. Patients with active hepatitis B (HBV), hepatitis C (HCV), and other acquired and congenital immunodeficiency diseases;
6. Patients with severe active infection who require systemic antibiotic treatment;
7. Have a history of serious neurological or psychiatric diseases, unable to participate in the trial normally, including dementia, epilepsy, severe depression and mania, etc.;
8. Drug abuse, medical, psychological or social conditions that may interfere with the subject's participation in the research or the evaluation of the research results;
9. Patients considered by the investigator to be unsuitable for enrollment;

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