Concomitant Chemo-radiotherapy Followed by MIDLE Chemotherapy in Stage I/II Extranodal NK/T-cell Lymphoma

Inclusion Criteria: * patients were required to have a biopsy-proven diagnosis of nasal ENKTL * at least 18 years old * Ann Arbor stage IE or IIE * measurable disease * Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 life expectancy greater than 12 weeks * adequate hematologic (hemoglobin \> 9.0 g/dL, absolute neutrophil count \> 1,500/uL and platelets \> 100,000/uL) * renal (serum creatinine \< 1.5 mg/dL, creatinine clearance \> 50 mL/min) * hepatic (total bilirubin \< 2 times of upper limit of normal and aspartate transferase \< 3 times of upper limit of normal) function * Diagnosis of ENKTL is based on the presence of histological features and immunophenotypes compatible with ENKTL (e.g., cytoplasmic CD3+, CD20-, CD56+, * positive for cytotoxic molecules * positive for EBV by in situ hybridization). * Informed consent Exclusion Criteria: * prior or concomitant malignant tumors * any coexisting medical problems of sufficient severity to prevent full compliance with the study protocol. * ENKTL with non-nasal sites such as skin or gastrointestinal tract was excluded even if it is localized. * Other subtypes of non-Hodgkin lymphoma (NHL), including myeloid/NK cell precursor acute leukemia, blastic NK cell lymphoma/precursor NK cell lymphoblastic leukemia, aggressive NK cell leukemia, and peripheral T cell lymphoma, unspecified, were excluded.