Purpose/Objective: To determine the risk of nodal relapse after complete clinical response to definitive radiation and to assess the role of neck dissection in those who had a partial response.Materials & Methods: Between 1970-1995, 174 patients who had SCCA of the supraglottic larynx with clinical positive neck received radiation treatment at our institution. 81 patients whom were treated with definitive radiotherapy were included in this study. Patients that received pre-operative, post-operative radiation, or excisional nodal biopsy before radiation were excluded. There were 57 males and 24 females with a median age of 62. The stage distribution was as follows: N1-36, N2-41 (2a-14, 2b-10, 2c-17), N3-4. The median nodal size was 3 cm (range 0.8-7.5). The median follow-up was 27.4 months (range 2.4-180 months). 4 patients received concurrent or neoadjuvant chemotherapy. 21 patients were treated with 60 Gy in 1.8-2.0 Gy per fraction once a day. 60 patients were treated with accelerated hyperfractionation to a total dose of 67.2-72 Gy/1.6 Gy BID in 40-42 days. The clinical nodal response was assessed at a median time of 7.2 weeks after completion of the radiation treatment. Patients whose lymph nodes that were not clinically detectable (complete response, CR) were followed without any planned neck dissection. Patients with persistent lymph nodes (partial response, PR) underwent planned neck dissection whenever possible.Results: 70% (5781) had a CR and 30% (2481) had a PR. Achieving a complete regional response was correlated with N-stage (92% N1, 61% N2, 50% N3). The nodal control probability at 3 years when the primary tumor was controlled (n=56) in the CR group was 84% for lymph node size < 3 cm (n=31), 88% for > 3 cm (n=26), 83% for N1 (n=33), and 94% for N2 (n=22) (p=0.5). 6 patients in the CR group had isolated regional recurrence (11%); 3 ipsilateral and 3 contralateral. 3 out of 4 patients who underwent neck dissection were salvaged. In the PR group, the nodal control probability at 3 years was significantly lower than the CR group, 57% vs 86% (p=0.02). Neck dissections were performed in 19 of the 24 patients who had a PR, and 13 patients (68%) had pathologic complete response. One patient with pathologic complete response had isolated regional recurrence (8%). 3 out of 5 patients who were pathologic positive achieved neck control. The 6 patients that did not undergo surgery received chemotherapy or further radiation and all had progression of neck disease.Conclusions: (1) Patients with clinically palpable cervical nodal metastases who have a complete clinical response after definitive radiotherapy have excellent neck control. Planned neck dissection should not be routinely done in this group of patients. (2) The risk of relapse after complete clinical response does not appear to be related to initial lymph node size. (3) Residual palpable adenopathy after radiation is not a good predictor of pathologically positive disease.