Purpose: Radiation therapy is the most important treatment for early nasal NK/T-cell lymphoma, but there are still some cases of relapse after radiotherapy. Based on the experience of more than 300 previous cases, our research group designed a new local expanded field intensity modulated radiotherapy target outline protocol for early primary nasal NK/T-cell lymphoma and applied it to 21 patients first, which showed good applicability and low toxic side effects. METHODS: Twenty-one patients with early-stage nasal NK/T-cell lymphoma, aged 13-61 years (median 43 years), 14 males and 7 females, enrolled in radical radiotherapy between October 2011 and March 2013, were studied by prospectively designing a uniform target-area outline and dose setting protocol. 14 patients were in Ann Arbor stage IE and 7 patients in stage IIE. All patients received induction chemotherapy combined with radical radiotherapy in 1-6 chemotherapy cycles (median 3 cycles). All patients were treated with individualized target settings, local expanded field intensity-modulated radiotherapy and consistent radiotherapy doses: gross tumor target area (GTV): 54.6 Gy/26f, high-risk clinical target area (CTV1): 50.7 Gy/26f and low-risk clinical target area (CTV2): 45.5 Gy/26f, and their dose distribution, recent efficacy and side effects were analyzed. RESULTS: The follow-up cut-off date was April 30, 2014, with a follow-up period of 7.0-30.0 months (median 24.3 months) and a follow-up rate of 100%. The results showed a 2-year local control rate of 100% and 2-year overall survival (OS) and progression-free survival (PFS) of 90.5% in the entire group. The results of the dose analysis showed that the median target area volume covered by 90% of the prescribed dose was 99.8%, 99.6% and 99.7% for PTV54.6Gy, PTV50.7Gy and PTV45.5Gy, respectively, and 99.5%, 99.2% and 99.5% for 95% of the prescribed dose, respectively, which achieved good target area coverage while the adjacent normal tissue did not exceed the safe The dose limits were not exceeded. No side effects of degree 3/4 were observed in the whole group of patients. CONCLUSION: The higher dose, three-dose gradient local expanded field intensity-modulated radiotherapy target-area outlining protocol developed by our study group not only achieved good target-area coverage, but also ensured low irradiation of surrounding normal tissues and mild side effects in patients, and resulted in a desirable 2-year local control rate for early NC-NKTL patients. Further studies and refinements are underway (we have accumulated more than 50 cases so far, with only one local recurrence).