Radiation Therapy

Radiation therapy for nasopharyngeal cancer frequently causes OME, which can lead to conductive hearing loss. Rates of OME range from 29% to 53% with intensity-modulated radiation therapy (IMRT)

Younger patients (especially under 4 years old) are at higher risk for hearing problems due to radiation therapy

Radiation therapy for head and neck cancers often damages the cochlea or acoustic nerve, leading to sensorineural hearing loss (SNHL). SNHL is dose-dependent, progressive, and typically permanent.

While some cases of radiation-induced conductive hearing loss may improve over time, others—especially those involving fibrosis or ossicular damage—can result in long-term or permanent hearing impairment

Low-Dose Radiation:

• Even low-dose radiation can affect hearing, but the impact is generally less severe compared to high doses. Studies show that individuals exposed to low-dose radiation may experience subtle changes in hearing thresholds, particularly at high frequencies (e.g., 4-16 kHz) due to vascular or cochlear changes[1].

• Middle ear function i

In summary, the likelihood and severity of hearing loss increase significantly with higher radiation doses, particularly when exceeding 50 Gy to auditory structures. Regular audiometric monitoring during and after treatment is essential for early detection and management.

Higher doses of radiation (>46 Gy to the middle ear or >52 Gy to the ET isthmus) significantly increase the likelihood of developing conductive hearing loss[

External Ear Canal Stenosis:

• Radiation may lead to narrowing (stenosis) of the ear canal, which can block sound from reaching the eardrum

Treatment of vestibular schwannomas with stereotactic radiosurgery or fractionated stereotactic radiation therapy can result in SNHL