Auditory brainstem responses after radiotherapy for nasopharyngeal carcinoma

The effect of irradiation for nasopharyngeal carcinoma on auditory brainstem responses and hearing was investigated in 19 otologically normal patients undergoing standard fractionated megavoltage radiotherapy. Auditory brainstem responses and pure tone audiometry were performed before radiotherapy, and at 3 and 12 months after completion of radiotherapy. There were no significant changes in the wave I-III and III-V interpeak intervals, or in sensorineural hearing thresholds (bone conduction at 4 kHz and average of bone conduction at 0.5, 1, 2 and 4 kHz), after radiotherapy. In contrast to previous studies, we found no evoked potential evidence of subclinical brainstem damage arising from irradiation for nasopharyngeal carcinoma.