Comparisons of the clinical outcomes of different postoperative radiation strategies for treatment of head and neck squamous cell carcinoma.

ABSTRACT

PURPOSE: We previously reported unfavorable locoregional control with limited field postoperative radiotherapy for head and neck squamous cell carcinoma patients and thus revised the strategy to cover the whole neck. Head and neck squamous cell carcinoma Patients' outcomes were retrospectively analyzed to compare the efficacy of two treatments. MATERIAL AND METHODS: Before 2010, the clinical target volume covered the tumor bed and/or involved the neck region. Since 2011, whole-neck irradiation was planned. Univariate analysis, multivariate analysis, and propensity score matching were performed. The study included 275 patients 186 received limited field postoperative radiotherapy and 89 received whole-neck postoperative radiotherapy. The median follow-up time for the entire cohort was 40.8 months. RESULTS: In univariate analysis, the radiation strategy had no significant effect on overall survival and progression-free survival. In multivariate analysis, whole-neck postoperative radiotherapy was a favorable factor for overall survival, progression-free survival, and locoregional control. Propensity score matching resulted in a cohort comprising 118 well-matched patients evenly divided between the limited field postoperative radiotherapy and whole-neck postoperative radiotherapy groups. Whole-neck postoperative radiotherapy group achieved a significantly better 2-year overall survival (56.4% vs. 78.1%; P = 0.003), 2-year progression-free survival (34.7% vs. 59.8%; P = 0.009), and 2-year locoregional control (54.4% vs. 83.2%; P < 0.001). The limited field postoperative radiotherapy group developed significantly more locoregional recurrences both in-field (35.2% vs. 15.1%, P = 0.003) and out-of-field (25.0% vs. 0%, P < 0.001) in the matched-pair cohort. CONCLUSION: Whole-neck postoperative radiotherapy is a more appropriate choice than limited field postoperative radiotherapy to improve overall survival, progression-free survival and locoregional control.