Lymph Node Yield in Therapeutic Neck Dissection: Impact of Dissection Levels and Prior Radiotherapy.

OBJECTIVE: Lymph node yield in therapeutic neck dissection is clinically significant and incompletely studied. We quantified node yield based on extent of neck dissection and presence of preoperative radiation. We also evaluated factors affecting incidence of extracapsular spread (ECS).

METHODS: Retrospective review of 499 patients undergoing therapeutic neck dissection; 414 patients met inclusion criteria and were divided into 2 groups: neck dissection alone or before radiation (surgery first: 280 patients; 385 dissections) and primary radiation before surgery (radiation first: 134 patients; 157 dissections). Node yield relative to levels dissected and incidence of ECS were examined.

RESULTS: Dissection-specific node yield was greater in the surgery first group for dissection of levels I-V (31.1 ± 16.7 vs 24.0 ± 14.7, P < .001) and levels II-V (26.7 ± 14.4 vs 21.1 ± 10.7). Extracapsular spread incidence was 32.1% (98/305) in the surgery first group and 15.4% (23/149) in the radiation first group ( P < .001).

CONCLUSION: This study clarifies anticipated node yield based on number of levels dissected and presence of preoperative radiation. Node yield and incidence of ECS are lower in patients undergoing preoperative radiation.