Effects of radiation on the temporal bone in patients with head and neck cancer

Abstract

Radiotherapy is a key component in the treatment of many head and neck cancers, and its potential to cause long-term adverse effects has become increasingly recognized. In this review, we describe the short-term and long-term sequelae of radiation-associated changes in and injury to the temporal bone and its related structures. The pathophysiology of radiation-induced injury and its clinical entities, including sensorineural hearing loss, chronic otitis media, osteoradionecrosis, and radiation-associated malignancies, are described. We also discuss radiation dose to the head and neck as it relates to these conditions. An improved understanding of radiation's effects on the temporal bone will enable physicians and researchers to continue efforts to reduce radiotherapy-related sequelae and guide clinicians in diagnosing and treating the various otologic conditions that can arise in patients with head and neck cancer who have received radiotherapy. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1428-1435, 2016.

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].…”

“…Radiotherapy is most used in head and neck cancer and the longterm adverse effects has become increasingly recognized [3]. One of the side effects is hearing loss, which is characterized by changes in the Organ of Corti described in hair cells, cochlea, stria vascular and cochlear neurons.…”

“…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].…”

“…To improve patients` life it is essential monitoring hearing thresholds during the early diagnosis of cochlea damage [3,8]. So the objective of this research is to evaluate hearing thresholds in subjects receiving radiotherapy as treatment for head and neck cancer.…”