Oncologic effectiveness of selective neck dissection in the N0 irradiated neck.

BACKGROUND The incidence and patterns of nodal spread in previously irradiated N0 necks are not well defined. Therefore, the safety and efficacy of selective neck dissection (SND) in this patient population is not well established. In a previous report from our institution, SND in irradiated patients with recurrent disease at the primary site but clinically negative necks resulted in excellent tumor control in the neck. The objective of this study is to validate our initial observations in a larger sample of patients with longer follow-up. METHODS A retrospective chart analysis of patients previously treated with primary radiation therapy or chemoradiotherapy for squamous cell carcinoma (SCC) of the head and neck between January 1997 and June 2003 was performed. Patients with recurrent or persistent disease at the primary site or a second primary head and neck SCC, with no clinical or radiologic disease in the neck, who underwent surgical salvage with resection of the primary site along with a site-specific SND were analyzed. Patients who remained disease free at the primary site were analyzed for regional control after SND. RESULTS Sixty-nine patients underwent a total of 96 site-specific SNDs. The mean age was 64.1 years (range, 39-91 years). There was histologically positive nodal disease in 17 of 69 patients (25%), and 22 of 96 necks (23%). Fifty-three patients had at least a 12-month follow-up. The mean follow-up was 23.3 months (range, 1-96 months). Of the patients with 1-year of follow-up, six patients died from recurrence at the primary site, and nine died from distant metastasis. There were no cases of neck recurrence with the primary site controlled. All patients who had more than two positive nodes had recurrence either at the primary site or distant metastasis. CONCLUSIONS Our results confirm that the patterns of lymphatic spread are not affected by radiation. We conclude that SND is oncologically safe in the management of the N0 irradiated neck and that the finding of more than two positive nodes predicts a poor outcome.