Obstructive versus patulous Eustachian tube dysfunction after head and neck radiotherapy

To characterize obstructive and patulous Eustachian tube dysfunction (ETD) phenotypes after head and neck radiotherapy and evaluate their associations with post-treatment stage and clinical factors.

This cross-sectional study enrolled 100 adults who had completed intensity-modulated radiotherapy for head and neck cancer. Patients were categorized by time since radiotherapy (< 3 months, 3 months-1 year, 1-3 years, and > 3 years). ETD phenotypes were classified as obstructive ETD (OETD), patulous ETD (PETD), or neither using symptom assessment and objective testing.

ETD phenotype distribution differed significantly across post-radiotherapy stages (p = 0.018). OETD was most common within 3 months (7/18 [38.9%]) and less frequent after > 3 years (5/44 [11.4%]), whereas PETD was more frequent at 1-3 years (3/16 [18.8%]) and > 3 years (9/44 [20.5%]). Among 13 patients with PETD, 12 (92.3%) reported improvement with forward bending or lying down. In exploratory logistic regression, the association between later post-radiotherapy stage and PETD was attenuated after adjustment for nasopharyngeal cancer (NPC) status (adjusted odds ratio [OR], 1.75; 95% confidence interval [CI], 0.84-3.66; p = 0.137), whereas NPC remained associated with PETD (adjusted OR, 9.47; 95% CI, 2.49-36.04; p < 0.001).

OETD was more prominent in earlier post-radiotherapy cohorts, whereas PETD was more frequently identified during longer-term follow-up. The apparent late-stage patulous pattern was substantially influenced by NPC status. These findings provide a hypothesis-generating framework for post-radiotherapy ETD and support phenotype-directed clinical evaluation.