Postirradiation otitis media with effusion in nasopharyngeal carcinoma patients treated by intensity-modulated radiotherapy.

OBJECTIVES/HYPOTHESIS Postirradiation otitis media with effusion (OME) is a common adverse otologic effect in nasopharyngeal carcinoma (NPC) patients treated by radiotherapy. The purpose of this study was to determine the long-term incidence of postirradiation OME in NPC patients following intensity-modulated radiotherapy (IMRT) and to evaluate the potential factors associated with the development of this otologic complication. STUDY DESIGN Retrospective observational study. METHODS A retrospective review of NPC patients treated by IMRT between January 2002 and June 2008 was conducted. Otologic complications were regularly evaluated during follow-up. Presence of OME was detected by findings of otoscopic exam, pure-tone audiometry, impedance audiometry, and tympanocentesis. Incidence of postirradiation OME and relevant factors were analyzed. RESULTS A total of 105 patients (210 ears) were enrolled in the study. There were 34 patients (32.4%) with unilateral or bilateral postirradiation OME 3 years or more following radiotherapy. There was no correlation between the complication and the stage of primary tumor. The presence of pretreatment OME, however, was significantly associated with the development of postirradiation OME. Although there was no significant relationship between the radiation dose and post-treatment OME, the link with radiation toxicity was demonstrated by the finding that 28% of postirradiation OME developed in the ears contralateral to the side of primary nasopharyngeal tumor. CONCLUSIONS Postirradiation OME remains a common late toxicity in NPC patients treated by modern radiotherapy. Pretreatment injuries by the tumor and radiation-induced damages to the eustachian tube both play a major role in the development of the otologic complication.