Outcomes following oropharyngeal squamous cell carcinoma resection and bilateral neck dissection with or without contralateral postoperative radiotherapy of the pathologically node-negative neck

PURPOSE: There are no consensus guidelines regarding the postoperative treatment of the contralateral pathologically node-negative neck in oropharyngeal squamous cell carcinoma. This study aimed to determine if omission of postoperative irradiation of the contralateral pathologically node-negative neck affects oncological outcomes. METHODS: We retrospectively identified 84 patients with primary surgical treatment including bilateral neck dissection and postoperative (chemo-)radiotherapy (PO(C)RT). Survival was analyzed using the log-rank test and the Kaplan–Meier method. RESULTS: Patients showed no decrease in tumor-free, cause-specific (CSS), or overall survival (OS) when PO(C)RT of the contralateral pathologically node-negative neck was omitted. Increased OS was found in patients with unilateral PO(C)RT and especially an increased OS and CSS was found in unilateral PO(C)RT and in tumors arising from lymphoepithelial tissue. CONCLUSIONS: Omitting the contralateral pathologically node-negative neck appears to be safe in terms of survival and our retrospective study advocates further prospective randomized control de-escalation trials.