Concomitant Chemo-radiotherapy Plus VIDL Chemotherapy in NK/T-cell Lymphoma

This study is to evaluate the efficacy of risk-adapted treatment strategy for stage I/II extranodal NK/T cell lymphoma. The risk stratification is based on the Korean NK prognostic index. Thus, the group I/II will receive concomitant chemoradiation followed by VIDL chemotherapy. The group III/IV will receive high dose-chemotherapy followed by autologous stem cell transplantation after the completion of VIDL chemotherapy.