Middle Ear Bacterial Colonization and Recurrence of Radiation‐Induced <scp>OME</scp> : A Prospective Study

OBJECTIVE: To define the bacteriological characteristics of otitis media with effusion (OME) in nasopharyngeal carcinoma (NPC) patients following radiotherapy and determine whether bacterial colonization in the middle ear was associated with a higher risk of early recurrence of radiation-induced OME (RI-OME). METHODS: This prospective multicenter cohort enrolled patients with OME (with or without a history of radiotherapy for NPC) undergoing tympanocentesis. Middle ear effusion (MEE) samples were cultured and patients with RI-OME were followed up for 24 weeks. Data on demographics, radiotherapy history, treatment, comorbidities, and effusion characteristics were collected. Recurrence patterns were characterized descriptively throughout the 24-week post-tympanocentesis follow-up. RESULTS: A total of 93 RI-OME patients and 115 non-radiation-induced (NRI)-OME patients were included. RI-OME patients had a 4.843-fold higher risk of MEE bacterial culture positivity compared to NRI-OME patients (OR = 4.843, p = 0.006). MEE cultures in RI-OME patients showed higher proportions of opportunistic pathogens and drug-resistant bacteria. Mucoid effusion was a significant risk factor for bacterial positivity in RI-OME (OR = 8.553, p = 0.002). Male sex (OR = 12.120, p = 0.002) and bacterial colonization (OR = 10.239, p = 0.035) were associated with early recurrence (≤ 4 weeks post-tympanocentesis) in RI-OME patients; however, neither factor remained an independent predictor over the full 24-week period. CONCLUSION: RI-OME patients demonstrated significantly higher MEE bacterial culture positivity rates than NRI-OME patients. Although MEE bacterial colonization significantly impacted early recurrence, it lacked independent prognostic value for overall 24-week recurrence. Thus, whether targeted antibacterial therapy can reduce recurrence rates warrants further investigation.