Cochlea Radioative Injury after Radiotherapy for Nasopharyngeal Carcinoma with Distortion Product Otoacoustic Emission

To study the value of distortion product otoacoustic emission(DPOAE) audiogram on examining the radioation injury to the cochlea after radiotherapy for nasopharyngeal carcinoma(NPC). DPOAE and pure audiometry were detected for 40 ears of NPC patients at regular intervals radiotherapy, (before, during, at the end 6 and 12 months after radiotherapy). The different intervals' data were collected and analyzed with statistic methods. Compared with DPOAE audiogram before radiation[1 0 kHz was (9 9±4 9) dB,2 0 kHz was (-0 7±8 6)dB,4 0 kHz was (2 9±6 2) dB,6 0 kHz was (1 4±7 4dB)],DPOAE audiogram of the different intervals were not the same,but there were on significant after difference(P0 05). The value of DPOAE was similar with the audiometric threshold of bone conduction.[Conclusion] DPOAE can be used in detecting the radiation injuries to the cochlea after radiotherapy. It is simple, objective, sensitive and unwounded.