[Damage to inner ear function caused by the effect of ionizing rays].

In the literature the inner ear is claimed to be resistent to the effects of ionizing irradiation. We therefore studied the inner ear function in a group of 49 patients who had undergone radiotherapy for malignant tumors of the head in which the irradiated field included at least one inner ear. 67 ears had been irradiated, 46 of them showed a sensorineural hearing loss of 10 dB or more. The frequency and the degree of the inner ear damage was correlated with the dosage of the irradiation and with the time elapsed after the end of radiotherapy.