Relative contributions of radiation and cisplatin-based chemotherapy to sensorineural hearing loss in head-and-neck cancer patients.

Purpose: To investigate the risk of sensorineural hearing loss (SNHL) in patients with head-and-neck cancer and treated with radiation therapy (RT) or concomitant cisplatin-based chemoradiation, the relationship among SNHL and radiation dose to the cochlea, the use of two common cisplatin dose regimens.

Methods And Materials: A total of 62 head-and-neck cancer patients treated with curative intent were included in this prospective study. Of the patients, 21 received RT alone, 27 received 40 mg/m(2) weekly cisplatin, 13 received 100 mg/m(2) every 3 weeks during RT, and 1 received RT with weekly epidermal growth factor receptor inhibitor antibody. The effect of chemotherapy and RT dose on hearing was determined using a model that accounted for the age and variability between each ear for each patient.

Results: We constructed a model to predict dose-dependent hearing loss for RT or cisplatin-based chemotherapy either alone or in combination. For patients only receiving RT, no significant hearing loss was found at doses to the cochlea of less than 40 Gy. Patients receiving 100 mg/m(2) or 40 mg/m(2) of cisplatin chemotherapy had an estimated +21.5 dB and +9.5 dB hearing loss at 8,000 Hz with low radiation doses (10 Gy), which rose to +38.4 dB and +18.9 dB for high radiation doses (40 Gy).

Conclusions: Use of RT alone with doses of less than 40 Gy did not result in clinically significant hearing loss. High-frequency SNHL was profoundly damaged in patients who received concomitant cisplatin when doses of 100 mg/m(2) were used. The threshold cochlear dose for hearing loss with cisplatin-based chemotherapy and RT was predicted to be 10 Gy. The inner ear radiation dose constraints and cisplatin dose intensity should be considered in the treatment of advanced head-and-neck cancer.