The promising outcome with simultaneous integrated boost intensity modulated radiotherapy in confined nasal extranodal NK/T-cell lymphoma

The study aimed to retrospectively analyze the prognosis of patients with stage IE nasal extranodal natural killer/T-cell lymphoma (ENKTL) with dose reduction to clinical target volume (CTV) by using simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT). Forty-four patients were reviewed retrospectively. The prescribed dose was 45 Gy/25 fractions for extended involved-field site and 50-55 Gy/25 fractions for primary tumor site by using SIB-IMRT. The 5-year overall survival (OS), local control (LC) and progression-free survival (PFS) were 81.2%, 93.0%, and 78.8%, respectively. The complete response (CR) rate was 85.4% (37/44). Three patients (6.8%) patients had local failure and 3 (6.8%) patients developed systemic failure. There was only one patient had grade 3 mucositis and 2 patients had grade 3 or grade 4 hematologic toxicities. For patients with stage IE nasal ENKTL, appropriate dose reduction to CTV by SIB-IMRT strategy is feasible and safe with a promising outcome.