Planned post-chemoradiation neck dissection: significance of radiation dose.

Objective: The increasing prominence of multimodality therapy for patients with advanced head and neck cancer reflects its high survival and functional preservation rates. We report the pathologic data on patients undergoing neck dissection (ND) after induction chemotherapy followed by concomitant chemoradiotherapy (IC-CRT) in three similar protocols utilizing decreasing doses of radiation therapy.
Materials and Methods: The databases of 221 patients who underwent IC-CRT between 1999 and 2002 were reviewed. Based on posttreatment residual or pretreatment N2a or greater neck disease, 73 patients without pretreatment neck surgery were eligible for analysis (1 N1, 3 N2a, 26 N2b, 20 N2c, 23 N3). Three additional subgroups were also analyzed with respect to outcome: Undissected patients with less than N2 disease, patients who had neck surgery prior to IC-CRT, and patients with N2a or greater neck disease who did not have post-IC-CRT ND.
Study Design: Retrospective analysis.
Results: Sixty-seven patients underwent unilateral or bilateral selective neck dissection. Six patients had modified or radical ND. There were no wound healing complications. Pathologic analysis revealed viable cancer in 15 of 73 patients (20.5%): 1 had N1, 3 had N2b, 4 had N2c, and 7 had N3 neck disease. The incidence of viable cancer in the neck dissection specimen increased as radiation dose decreased. Complete response induction chemotherapy predicted negative pathology (P = .003). In the subgroup analysis, patients who had pretreatment surgery had a lower risk of dying from the primary cancer
Conclusions: 1) The incidence of positive pathology after IC-CRT increases as radiation dose decreases. 2) Selective neck dissection after CRT has been demonstrated to be feasible and safe; the complication rate of ND after IC-CRT is acceptably low. 3) There is viable posttreatment cancer in 20.5% of patients, indicating necessity of ND in these patients.