Extranodal natural killer (NK)/T-cell lymphoma (ENKTL), nasal type, is a distinct and
heterogeneous histopathologic subtype of non-Hodgkin lymphoma (NHL), accounting for 5%~10%.
The frequency of ENKTL among NHL patients is significantly higher in Asia than in Western
countries, with poor prognosis. Radiotherapy plus chemotherapy has improved the survival for
these patients. But the optimal treatment schedule is controversial. The previous protocols
usually contained high dose methotrexate, but the application of them is limited for the