Objective Swallowing Outcomes After Sparing Contralateral Low-Neck Elective Radiotherapy in Oropharyngeal Carcinoma: Single-Institution Clinical Experience.

OBJECTIVE: Dysphagia is a major toxicity of chemoradiation (CRT) for oropharyngeal squamous cell carcinoma (OPSCC). Elective upper-neck irradiation (UNI), omitting the low neck, may reduce esophageal inlet muscle (EIM) dose and improve swallowing outcomes compared to elective whole-neck irradiation (WNI). We compared swallowing outcomes after UNI versus WNI. STUDY DESIGN: Retrospective review from 2015 to 2023. SETTING: Tertiary academic center. METHODS: We retrospectively reviewed OPSCC patients treated with definitive CRT who underwent baseline and post-treatment videofluoroscopic swallow studies (VFSSs). Outcomes included swallowing kinematics, functional VFSS measures, feeding tube placement, and recurrence. RESULTS: Fifty-two patients with p16-positive OPSCC were included: 28 (54%) UNI and 24 (46%) WNI. T and N stages were balanced between treatment groups. Supraglottic, glottic, and constrictor doses were similar between UNI and WNI. EIM dose was lower in UNI than WNI (29.8 vs 36.1 Gy, P = .011). UNI was associated with a lower incidence of feeding tube placement during/after CRT than WNI (22% vs 57%, P = .00643) and reduced hazards of feeding tube placement at 1 year post-CRT when adjusted for T/N stage and EIM dose (hazard ratio [HR] 0.25, P = .006). No differences were seen in the incidence of esophageal dilation, pneumonia, or recurrence. No disease relapse was observed in the omitted contralateral low neck. CONCLUSION: UNI was associated with reduced EIM dose and lower rates of feeding tube placement compared to WNI, without compromising disease control. In OPSCC patients requiring elective contralateral neck irradiation, omitting the contralateral low neck is a promising de-escalation strategy.