Late effects of radiotherapy on hearing.
The effect of radiotherapy on hearing was studied in 30 patients who were treated by surgery and radiotherapy for a parotid neoplasm. Functions of the irradiated ear were compared with those of the non-irradiated ear in the same patient. Tympanometry showed a small but significant reduction of static compliance on the irradiated side when compared with the non-irradiated side. Audiometry showed a significant increase in hearing loss in the 1-2, 4-8 and 10-20 kHz ranges that increased with frequency. This hearing loss was mainly sensorineural in contrast to hearing loss at 250-500 Hz, where it was more of a conductive type. There appeared to be a significant dose-effect relation in sound perception at 4-8 kHz. Doses to the cochlea of less than 55 Gy seldom caused a hearing loss, in contrast to doses exceeding 65 Gy. Overall, radiotherapy was found to cause significant, mainly sensorineural hearing losses, which were partly dose-dependent.
Schot
L J
LJ
Department of ENT/Head and Neck Surgery, The Netherlands Cancer Institute, Amsterdam.
Hilgers
F J
FJ
Keus
R B
RB
Schouwenburg
P F
PF
Dreschler
W A
WA
D000158:Acoustic Impedance Tests; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001301:Audiometry, Pure-Tone; D004307:Dose-Response Relationship, Radiation; D004423:Ear / Q000528:radiation effects; D005260:Female; D006311:Hearing Disorders / Q000175:diagnosis / Q000209:etiology*; D006319:Hearing Loss, Sensorineural / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010307:Parotid Neoplasms / Q000532:radiotherapy; D011878:Radiotherapy / Q000009:adverse effects*