Mechanisms of radiation-induced sensorineural hearing loss and radioprotection

Effects in Hearing Thresholds in Subjects Receiving Radiotherapy as Treatment for Head and Neck Cancer

“…Electrons are displaced in cancer tissues, by ionization, cause chemical and biological effects, such as DNA damage, that prevent the replication of neoplastic cells. It acts directly on the tumors and stops their multiplication by mitosis and/or determine cell death [3,6,14]. The literature also evince that chemoradiotherapy improves patient survival [15,16], but our participants had advanced cases and medical team reported the radiation therapy as an efficient procedure in cancer treatment.…”

“…Cancer treatment has ototoxic effects that can damage hair cells, so it initially affects high frequencies, and it can also endanger low frequencies as a result of treatment exposure [3,5,14]. Literature reports an incidence of 26% and 85% of hearing loss, once 95% of hearing losses are sensorioneural [6]. Moreover, the present study was characterized of pure tone audiometry evaluation, despite being a conventional study, frequencies of the diagnosis of hearing loss were evident, as studies with high frequencies audiometry and otoacustic emissions [6,20,21].…”

“…It´s important in radiation therapy protect the cochleo vestibular apparatus [4] once the literature reports changes in hearing thresholds. Most cases are sensorioneural type and first affect higher frequencies and may subsequently affect mid and low frequencies [5,6].…”

“…Radiotherapy ototoxic effect can be developed immediately, so the patient can have a middle ear disease due to the radiation as known as a conductive hearing loss; or ultimately, characterized by changes in Organ of Corti, specifically in outer hair cells, which can appear months or years after the treatment onset [3,6,7].…”

Id1/NR2B Receptor Pathway Regulates Rat Cochlear Sensory Epithelial Cell Survival after Radiation

“…Although cochlear hair cell survival has been shown to be affected by the p53-dependent apoptotic pathway and by reactive oxygen species after radiation [Mujica-Mota et al, 2014], the mechanisms involved in radiation-related damage may be more complex and may involve other factors, such as inhibitor of differentiation-1 (Id1) [Anido et al, 2010] and the N-methyl-D-aspartic acid (NMDA) receptor [Chen et al, 2014].…”