Low risk of contralateral lymph node recurrence in lateralized head and neck carcinoma after postoperative ipsilateral radiotherapy.

The role of postoperative irradiation to contralateral non-involved neck nodes in lateralized carcinoma of the head and neck is not clear. The contralateral neck failure rate in head and neck carcinoma treated postoperatively with ipsilateral neck irradiation only was evaluated. Patients with carcinoma of the oral cavity, oropharynx, or hypopharynx without midline extension treated between 1990 and 2016 were analyzed. After tumor resection and neck dissection (ND), radiotherapy was given to the primary tumor site and ipsilateral neck. High-risk patients additionally received concurrent chemotherapy. Freedom from contralateral neck recurrence (FCNR), locoregional control rate (LRC), overall survival (OS), and disease-free survival (DFS) were evaluated. 197 patients (median age 60.7 years, 66.5% males, 52.8% oropharyngeal carcinomas) were analyzed. Complete resection (R0) was achieved in 85.8% of cases. Ipsilateral ND was performed in all patients and contralateral ND in 144 patients (73.1%). Concurrent chemotherapy was given to 59 patients (30.0%). After a median follow-up of 45.5 months, OS and DFS of all patients were 73.6% and 70.9% at 5 years, respectively. A total of 45 patients (22.8%) suffered from a locoregional recurrence, lymph node metastases of the contralateral neck developed in 12 patients (6.1%) only. There was no significant difference in contralateral nodal failure rate with or without performance of contralateral ND. Regional failure of the contralateral neck was low after surgery and ipsilateral neck irradiation in head and neck carcinomas without midline extension, supporting evidence that contralateral neck radiotherapy can safely be omitted in selected cases.