Risk factors for hearing loss in patients treated with intensity-modulated radiotherapy for head-and-neck tumors.
OBJECTIVE
Radiotherapy (RT) is a common treatment of head-and-neck carcinoma. The objective of this study was to perform a prospective multivariate assessment of the dose-effect relationship between intensity-modulated RT and hearing loss.


METHODS
Pure tone audiometry at 0.250-16 kHz was obtained before and after treatment in 101 patients (202 ears). All patients received full-course intensity-modulated RT (range, 56-70 Gy), with a median cochlear dose of 11.4 Gy (range, 0.2-69.7).


RESULTS
Audiometry was performed 1 week before and a median of 9 weeks (range, 1-112) after treatment. The mean hearing deterioration at pure tone average air-conduction 1-2-4 kHz was small (from 28.6 dB HL to 30.1 dB HL). However, individual patients showed clinically significant hearing loss, with 10-dB threshold shift incidences of 13% and 18% at pure tone averages air-conduction 1-2-4 kHz and 8-10-12.5 kHz, respectively. Post-treatment hearing capability was unfavorable in the case of greater inner ear radiation doses (p <0.0001), unfavorable baseline hearing capability (p <0.0001), green-eyed patients (p <0.0001), and older age (p <0.0001). Using multivariate analysis, a prediction of individual hearing capabiltity after treatment was made.


CONCLUSIONS
RT-induced hearing loss in the mean population is modest. However, clinically significant hearing loss was observed in older patients with green eyes and unfavorable pretreatment hearing. In these patients, the intended radiation dose may be adjusted according to the proposed predictive model, aiming to decrease the risk of ototoxicity.
Zuur
Charlotte L
CL
Department of Otolaryngology/Head and Neck Surgery, VU University Medical Center Amsterdam, The Netherlands. cl.zuur@vumc.nl
Simis
Yvonne J
YJ
Lamers
Emmy A
EA
Hart
Augustinus A
AA
Dreschler
Wouter A
WA
Balm
Alfons J
AJ
Rasch
Coen R
CR
D000367:Age Factors; D001299:Audiometry; D004307:Dose-Response Relationship, Radiation; D007758:Ear, Inner / Q000528:radiation effects; D005127:Eye Color; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D034381:Hearing Loss / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D012307:Risk Factors