Chemoradiotherapy for localized extranodal natural killer/T-cell lymphoma, nasal type, using a shrinking-field...

The prognosis of localized extranodal natural killer/T-cell lymphoma, nasal type (ENKTL), has improved with the development of chemoradiotherapy. However, conventional extended-field radiotherapy may cause optic disorders. Our group has employed smaller radiation fields in an attempt to avoid toxicity. The efficacy and toxicity of treatments were evaluated.

Chemoradiotherapy was delivered with a shrinking-field radiotherapy strategy. The endpoints of this study were overall survival (OS), local control (LC), progression-free survival (PFS), and toxicity.

Fifteen patients with localized ENKTL were treated. After irradiation (median, 40 Gy) to the tumor plus a prophylactic volume, a reduced treatment volume to the tumor was boosted (median, 10 Gy). Twelve patients underwent chemoradiotherapy and 3 patients received radiotherapy alone. A complete response was achieved in 12 and a partial response in 3 patients. The 5-year OS, PFS, and LC rates were 80, 67, and 93 %, respectively. Distant recurrence occurred in 4 patients and locoregional and distant recurrence in 1 patient. Cataract (grade 3) and dry eye (grade 2) were observed as late adverse events in 1 patient each.

Sufficiently high OS and LC were achieved with acceptable toxicities. Appropriate target volumes may be smaller with newer chemotherapy regimens.