Association Between Eustachian Tube Obliteration Grade and Audiologic Outcomes in Patients with Nasopharyngeal Carcinoma

Abstract

Nasopharyngeal carcinoma (NPC) frequently involves the fossa of Rosenmüller and surrounding structures adjacent to the pharyngeal orifice of the Eustachian tube (ET), potentially causing ET dysfunction, middle ear effusion, and conductive hearing impairment. However, the association between radiologic ET obliteration severity and audiologic outcomes remains insufficiently explored. To evaluate the association between CT-based ET obliteration grade and audiologic outcomes in patients with NPC. A cross-sectional analytic observational study was conducted involving 26 patients that histopathologically confirmed NPC. ET obliteration was assessed using contrast-enhanced head and neck computed tomography (CT). Audiologic outcomes were evaluated using pure tone audiometry, average air-bone gap (ABG), and tympanometry. Correlation analyses were performed using Spearman’s rho test. The mean age of participants was 46.46 ± 12.34 years, with male predominance (57.7%). Grade 3 ET obliteration was the most common finding (42.3%), while type B tympanogram predominated (88.5%). Significant positive correlations were identified between ET obliteration grade and degree of hearing loss (r = 0.621; p < 0.001), as well as average ABG (r = 0.411; p = 0.037). No significant association was observed between ET obliteration and tympanogram type (p > 0.515). Tumor stage demonstrated a positive correlation with ET obliteration grade (r = 0.485; p = 0.012). Tumor volume was significantly associated with ET obliteration grade (r = 0.474; p = 0.014) and hearing loss severity (r = 0.537; p = 0.005). Greater ET obliteration severity on CT imaging was associated with worse audiologic outcomes in NPC patients. Radiologic assessment of ET obliteration may serve as a useful indicator of middle ear dysfunction and hearing impairment in NPC.