To Compare the Severity of Hearing Loss in Two Modalities of Treatment for Head and Neck Cancer Cases

Abstract

Background: Ototoxicity is the cellular degeneration of cochlear and/or vestibular tissues leading to its functional deterioration, due to the usage of certain therapeutic agents. The present study was undertaken to compare hearing loss in patients receiving radiotherapy alone and concurrent chemoradiation therapy was done. Materials & Methods: All patients with head and neck cancers who visited the Department of Otorhinolaryngology and Head and Neck surgery and undergone treatment, after histological confirmation, at the Department of Radiation Oncology at Sardar Patel Medical College, Bikaner, Rajasthan from November 2019 to October 2020 were taken up for the study. 80 patients who fulfilled the inclusion and exclusion criteria and given informed, written consent were divided into 2 groups, A and B of 40 each. Group A were treated with radiotherapy only and group B with concurrent chemoradiotherapy. Data was entered in Microsoft Excel and was subsequently imported to Statistical package for the social sciences (SPSS) free version 21.0 and Epi info version 3.0 for analysis. Results: Our study consisted of 80 subjects out of which 52 (65%) were male and 28 (35%) females. The age of the subjects ranged from 30 to 60 years, with highest number of patients belonged to the age group of 51-60 (57.5%) years. In our study, majority of the patients had carcinoma oral cavity (35%) followed by Larynx (28.75%), Hypopharynx (16.25%), Oropharynx (8.75%), Nose & PNS (6.25%), Nasopharynx and Occult primary with secondary neck (each 2.5%). In group A (RT), 50% had conductive hearing loss after completion of treatment which declined to 37.5% after 3 months follow up. Similarly, 45% developed conductive hearing loss after completion of treatment which also declined to 30% after 3 months follow up in group B (RT+CT). Otitis media with effusion and Eustachian tube dysfunction are temporary and reversible side effects of the irradiation of the ear. Conductive hearing loss develops as a reversible side effect of radiation of the ear. The impact of radiation dose on hearing loss was studied and was found that patients with radiation dose less than 60 Gy showed no hearing loss. Dose of the radiation is proportional to development of ototoxicity. Total radiation dose of minimum 60 Gy is required to produce noticeable ototoxic effects. On comparing the hearing loss, after completion of treatment with radiotherapy 30% developed significant hearing loss whereas in RT+CT group 45% had significant hearing loss while after 3 months follow up, 37.5% and 62.5% developed significant hearing loss in RT and RT+CT group respectively. The hearing loss was persistent. Statistical analysis was done, and it was found that there was significant difference in proportions of hearing loss due to RT and RT+CT (p<0.05) after completion of treatment and 3 months follow up. Conclusion: Thus, we conclude that patients who received concomitant chemoradiation experienced greater hearing loss as compared with patients treated with radiotherapy alone and hearing loss was predominately of sensorineural type. In our study, cobalt 60 teletherapy was used as a method of radiation administration and radiation induced such ototoxicity can be reduced by newer techniques of radiation administration that can limit the dose of radiation to cochlea and preventing hearing loss.