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.