Extranodal NK/T-cell lymphoma, nasal type (NKTCL) is a common malignant tumor in East Asian populations, often starting in the nasal cavity and spreading to other organs. Associated with EBV infection, NKTCL is aggressive. Early-stage patients typically receive chemo and radiotherapy, with promising outcomes. Recent studies show the potential of immune checkpoint inhibitors in NKTCL treatment. However, optimal treatment sequencing and efficacy remain unclear. This study aims to compare three strategies: (A) Pegaspargase with Sintilimab and radiotherapy; (B) chemo then radiotherapy (PGemOx); (C) sandwich chemoradiotherapy (GELAD). The goal is to identify the best treatment based on 24-month progression-free survival.

Extranodal NK/T-cell lymphoma, nasal type (NKTCL) is a malignant hematological tumor that is common in East Asian populations. The disease typically manifests in the nasal cavity in its early stages and can later involve multiple organs throughout the body. Highly associated with EBV infection, NKTCL is known for its aggressive nature. Currently, early-stage patients usually undergo combined treatment with chemotherapy and radiotherapy. Recent studies have shown that combining chemotherapy and radiotherapy containing asparaginase can achieve a complete remission rate (CR) of over 80%, with long-term survival rates exceeding 70% for patients. In recent years, researchers have found that immune checkpoint inhibitors demonstrate high activity in NKTCL, becoming an important therapeutic option. However, it is worth noting that the optimal sequence of chemotherapy and radiotherapy, as well as the effectiveness of combining radiotherapy with immunotherapy, have not been defined. Studies on different treatment strategies have shown variations in treatment-related adverse reactions and compliance with regimens among patients. However, there is currently no prospective randomized controlled study comparing the efficacy and safety of different strategies. Therefore, it is necessary to identify a treatment strategy with good efficacy and tolerability for patients. This study will stratify early-stage NKTCL patients using the NRI scoring system and randomly assign them to three different treatment strategies: (A) asparaginase combined with Sintilimab and synchronous radiotherapy; (B) sequential chemotherapy (PGemOx) followed by radiotherapy ; (C) chemotherapy (GELAD) with sandwiched chemoradiotherapy, to identify the best or worst treatment strategy based on the 24-month progression-free survival rate.

Inclusion Criteria:

• Patients who meet the diagnostic criteria for NKTCL (WHO-2016) based on pathological examination.
• Primary lesions located in the upper respiratory and digestive tract such as the nasal cavity, sinuses, nasopharynx, oropharynx, or oral cavity, with clinical staging of IE/IIE based on PET/CT and bone marrow examination according to the Lugano 2014 criteria.
• Evaluated for lymphoma response according to the Lugano 2014 criteria, with at least one measurable lesion or lesion assessable by PET/CT.
• No prior treatment with chemotherapy, radiotherapy, immunotherapy, or biological therapy for lymphoma.
• Age between 18 and 75 years, both genders.
• Eastern Cooperative Oncology Group performance status (ECOG) score of 0-2.
• Must have adequate organ and bone marrow function, defined as follows:

Hematology: Absolute neutrophil count (ANC) ≥1.0×10^9/L, platelet count (PLT) ≥75×10^9/L, hemoglobin (Hb) ≥90g/L; no administration of granulocyte colony-stimulating factor, platelet transfusion, or red blood cell transfusion in the previous 14 days.

Liver function: Total bilirubin (TBIL) ≤1.5 times the upper limit of normal (ULN); alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤2×ULN.

Renal function: Serum creatinine (Cr) ≤1.5×ULN. Coagulation function: Plasma fibrinogen ≥1.5g/L. Cardiac function: Left ventricular ejection fraction (LVEF) ≥50%, no acute myocardial infarction, arrhythmia, or atrioventricular conduction block of grade I or above on electrocardiogram.

• Willing to comply with the study protocol, follow-up plan, and laboratory and ancillary investigations.

Exclusion Criteria:

• Patients co-infected with HCV, HIV, or HBV with plasma HBV-DNA >10^3/ml.
• Patients with a history of pancreatitis.
• Patients with acute or systemic infections requiring intravenous antibiotic therapy.
• Patients with severe complications such as hemophagocytic syndrome, DIC, etc.
• Significant organ dysfunction: such as respiratory failure, chronic congestive heart failure with NYHA class ≥2, decompensated liver or renal dysfunction, uncontrolled hypertension and diabetes despite aggressive treatment, and cardiovascular thrombotic or hemorrhagic events in the past 6 months.
• Patients with a history of autoimmune diseases who are not suitable for treatment with immune checkpoint inhibitors.
• Pregnant and lactating women.
• Patients with psychiatric disorders.
• Known allergies to drugs in the chemotherapy regimen.
• Patients with concomitant other tumors requiring surgery or chemotherapy within the past 6 months.
• Currently using other experimental drugs.