Radiation effects on hearing and balance
There are many medical treatments that can cause problems with hearing and balance. Those treatments include ototoxic medications for the treatment of bacterial infections (including many of the aminoglycosides) and cancer (cisplatin), and radiation used to treat patients with brain tumors and head and neck cancers. Radiation to the head and neck area, including the middle and inner ear, can be problematic for hearing. There are two types of hearing loss that can be caused by this treatment, including conductive and sensorineural hearing loss.
Many patients who undergo radiation in the head and neck region will develop hearing loss post-treatment. – Audiology HealthCare News
Patients treated with radiation
A number of studies have reported that about one-third of patients treated with radiation in the middle/inner ear area will have sensorineural hearing loss. The loss usually develops three to five years following radiation, is greater in the higher frequencies, and is irreversible. A study investigated 141 patients with head and neck tumors who underwent radiotherapy, with another 141 patients as an age-matched control group. Hearing was tested two to 29 years post-treatment. Of those who received radiation, 72% had hearing loss. In the control group, 49% had hearing loss.
Radiation in the ear region
Radiation in the ear region can also affect the external or middle ear systems, leading to conductive hearing loss in about 40% of patients. Effects include skin reactions (ulceration, atrophy, otitis externa), reduction in cerumen production (ear wax), otitis media, and eustachian tube dysfunction. The most important risk factors for damage to hearing and balance are tumor location and the amount of radiation. If radiation is accompanied by cisplatin-based chemotherapy, the risk of hearing loss increases. This suggests that patients receiving radiation alone or radiation with cisplatin-based chemotherapy receive a baseline hearing test before treatment, following treatment, and every six months thereafter for at least five years.
Prevention and treatment
Preventative treatment for those exposed to cisplatin has yielded encouraging results. The US Food and Drug Administration is expediting the development and approval of Pedmark, a “breakthrough therapy” that treats hearing loss in children receiving cisplatin (ASHA Leader, July 2018). Staying on top of hearing health can be difficult when treating patients for serious medical conditions. Although the change in treatment may not be an option, early detection of changes in hearing allows the individual and family to prepare and cope with increased communication problems.
Source: Audiology HealthCare News
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