Prospective study of sensorineural hearing loss following radiotherapy for nasopharyngeal carcinoma

Abstract

To investigate the severity and incidence of sensorineural hearing loss in patients with nasopharyngeal carcinoma treated with radiotherapy. Forty-two patients with nasopharyngeal carcinoma were treated with conventional radiotherapy. Audiological testing was performed to compare patients' hearing before and at varying stages after radiotherapy. At one month post-radiation, a significant hearing threshold increase was seen only for high frequencies. At 12, 24 and 60 months post-radiation, significant threshold increases were observed at speech frequencies (4.0 and 8.0 kHz), compared with pre-radiation data. The mean values of wave I, III and V latencies and of the I-V interpeak latency intervals were not significantly altered at one month post-radiation, but were significantly prolonged at 12, 24 and 60 months post-radiation, compared with pre-radiation data. In patients with nasopharyngeal carcinoma treated with radiotherapy, the severity and incidence of radiation-induced sensorineural hearing loss increased with time, especially at high frequencies. This hearing impairment may be due to changes in the cochlea and/or the retrocochlear auditory pathway.