Long-term sensorineural hearing deficit following radiotherapy in patientssuffering from nasopharyngeal carcinoma: A prospective study

Background. This was a prospective study to evaluate the effect of radical external irradiation on inner ear function after treatment of nasopharyngea l carcinoma. Methods. Pure tone audiograms were performed at regular intervals before, a fter, and up to 4.5 years following completion of radiotherapy. Results. Two hundred ninety-four patients (526 ears) were included. Within 3 months after radiotherapy, deterioration of bone conduction threshold at 4 kHz and pure tone average (average of 0.5 kHz, 1 kHz, and 2 kHz) were not ed in 164 ears (31%) and 75 ears (14%), respectively. Patients older than 5 0 years and ears with threshold below 60 dB at 4 kHz before radiotherapy we re significant factors (p < 0.01 and p < 0.001) associated with a 4 kHz los s. in 40% of these ears, recovery was evident at 2 years. With follow-up fo r 4.5 years, the probability of significant threshold deterioration increas ed with time. Conclusion. Sensorineural hearing loss started soon after radiotherapy. Ear ly changes could be reversible while the probability of persistent hearing loss continued to increase.