GELAD Chemotherapy and Sandwiched Radiotherapy in the Treatment of Stage IE/IIE Natural Killer/T-cell Lymphoma

Inclusion Criteria: * Pathological diagnosis of extranodal natural killer/T-cell lymphoma, nasal type, previously untreated * Eastern Cooperative Oncology Group (ECOG ) performance status 0\~3 * Stage IE to IIE disease with at least one measurable lesion in the nasal cavity, paranasal sinuses, orbit, pharynx, Waldeyer's ring, or oral cavity. * Preserved organ functions for: absolute neutrophil counter (ANC)\>1.0×109/L, Platelet\>50×109/L, hemoglobin\>80g/L, total bilirubin (TBIL)\<2×ULN, alanine transaminase (ALT)\<2×ULN, serum creatinine\<1.5×ULN，fibrinogen≥1.0g/L, LVEF≥50% * No history of chemotherapy or radiotherapy. * Signed Informed consented Exclusion Criteria: * Concurrent cancers need surgery or chemotherapy within 6 months. * Significant complications: LVEF≤50%, coagulopathy, autoimmune disease, severe infection, or liver cirrhosis, hemophagocytic lymphohistiocytosis. * Mental disorders. * Pregnant or lactation * HIV, hepatitis virus C (HCV), or active hepatitis virus B (HBV) infection with HBV DNA≥105 copies/ml. * History of pancreatitis * Known history for grade 3/4 allergy to the drugs in chemotherapy regimen. * Enrolled in other trial treatment