Background: Radiotherapy is one of the important components of head and neck cancer (HNC) treatment. This treatment method may cause a variety of side effects like oral problems, swelling, and hearing loss. Objectives: In this study, the effect of radiotherapy on hearing loss in patients with HNC was investigated. Methods: In this prospective cohort research, patients with head and neck cancer referring to the Shohadaye Tajrish Hospital during 2014 to 2015 were investigated. All of these patients were candidate for radiotherapy as the main treatment. The radiotherapy of patients was done by 3D-computer based treatment planning system, using their CT scan. In order to oncologic assessment, preand post-radiotherapy audiologic evaluations were done. The common toxicity criteria for the adverse events (CTCAE V4.02) of the National Cancer Institute (NCI) were used for ototoxicity. A bivariate latent variable model was used to assess the effect of received dose on the severity of hearing loss. Results: In this study, 66 patients with HNC were investigated. Among them, 46 patients (70%) were male. The mean (SD) age of patients was 45.33 (15.11). The incidence rate of hearing loss in these patients was about 18%. The result of statistical modeling showed a positive relationship between severity of HL and received dose of radiation (P < 0.001).
Conclusions:In general, the findings of this study showed a direct relationship between radiation dose received by the ears and severity of hearing loss in patients with HNC. In this context, paying more attention to dose-prescription limits and standards for assessing radiation therapy associated ototoxicity are strictly recommended.