Spread patterns of lymph nodes and the value of elective neck irradiation for esthesioneuroblastoma.

Objectives: This study was aimed to characterize patterns of lymphatic spread and assess the value of prophylactic elective neck irradiation (ENI) for esthesioneuroblastoma (ENB).

Methods: A retrospectively analysis of 116 patients with newly diagnosed ENB at our institution over 35-year period was undertaken.

Results: 32 patients (28%) presented lymph node metastasis at initial diagnosis, the common sites involved were level II, Ib, level III and VIIa. Among 80 N-negative patients staged in Modified Kadish B/C, 50 patients were delivered with ENI, 30 patients were not. The 5-year regional failure-free survival was 98% in patients treated with ENI and 75% in patients without ENI (p=0.005), regional failure rate decreased significantly from 23% (7/30) to 2% (1/50) after ENI (p=0.002). Multivariate analysis also suggested that ENI was an independent favorable predictor for regional controlling (HR, 0.102; 95% CI: 0.012-0.848; p=0.035).

Conclusions: This is the largest cohort of ENB so far in a single institute, and also the first detailed description of nodal spread patterns of N-positive ENB. Elective neck irradiation reduced the regional failure significantly and should be recommended as a part of initial treatment strategy for patients staged with Modified Kadish B/C.