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

Abstract

Background One of the debilitating complications of head and neck cancer radiotherapy is hearing loss. Objective To quantify the magnitude of sensory neural hearing loss (SNHL) in the head and neck cancer patients undergoing chemoradiation therapy. Design and methods This is a prospective study. Eighty patients with head and neck cancers and undergoing volumetric arc therapy were taken up for the study. Regular audiological evaluation was done. The changes in audiological parameters from baseline are correlated with cochlear dose. Results Cochlea received maximum doses of up to 28.52 Gy without causing SNHL in the absence of chemotherapy. But in concurrent chemoradiotherapy, hearing loss was found at least dose of 9 Gy at frequency range of 4 KHz–8 KHz. The risk of SNHL is independent of cumulative doses of Cisplatin. In 106 ears receiving concurrent chemoradiation, 82.1% and 74.5% ears had sensorineural hearing loss at 4 KHz and 8 KHz respectively, following the completion of treatment. Otoacoustic emissions in the chemoradiation group showed a significant change at the completion of treatment. Conclusion and significance Volumetric arc therapy have facilitated sparing of cochlea (< 40 Gy). This has resulted in better clinical outcome in terms of SNHL. The inclusion of concurrent cisplatin chemotherapy is a significant risk factor for the development of SNHL at higher frequencies.