Audiometric patterns in ototoxicity after radiotherapy and chemotherapy in patients of head and neck cancers

Introduction: Inspite of various strategies adopted to protect the sensitive structures during organ preservation strategies, radiation damage can occur from the pharyngotympanic tube to the brain stem auditory pathway causing hearing loss. The purpose of this study is to evaluate the audiometric abnormalities and characterize them among the patients of head and neck cancers who have undergone radiotherapy (RT) and chemoradiation therapy (CT+RT). Materials and Methods: Sixty-six histopathologically proven head and neck cancer patients receiving RT and 34 patients receiving concomitant CT + RT underwent evaluation for audiometric abnormalities from 1 st September 2010 to 31 st August 2012. Results: Hearing losses were predominately of sensorineural type and mild. Patients who received concomitant CT+RT experienced greater sensorineural hearing loss compared with patients treated with RT alone. A paired sample t-test was conducted to compare the hearing losses before therapy and 6 and 12 months after therapy and was found to be significant ( P < 0.05). It was found that hearing loss was persistent. Significant difference was found in the proportion of hearing loss after RT and RT+CT ( P < 0.05) after 1 month. In addition, mixed hearing loss occurred due to damage to the middle ear contents and can be improved if intervened appropriately.