For phase II study, after reviewed the number of ENKTL patients in the Thai Lymphoma Study Group Registry, there were 106 newly diagnosed ENKTL patients in the registry from 2007-2013. This translated to approximately 15 newly diagnosed ENKTL patients per year. Since this study has the time for patient accruement of three years and with respect to the reference from other previous studies, the total approximate patients in this study for phase I and II is 36.