The Impact of Combined Modality Therapy on Sensorineural Hearing Loss in Patients with Head and Neck Cancer

The primary aim of this study is to develop a stratified risk model for patients who are most at risk of developing sensorineural hearing loss (SNHL). Participants will be allocated to a risk profile prior to their radiotherapy planning. These risk profiles include minimal risk of hearing loss and increased risk of hearing loss, with participant allocation based on tobacco and alcohol consumption, chemotherapy agent and cumulative chemotherapy dose. Participants in both risk profiles will have their chemotherapy delivered according to standard department protocol. Participants in both risk profiles will have their radiotherapy simulation conducted according to department protocol. This involves a CT scan, used to define organs and disease, lasting approximately 20 minutes. Participants assigned to the minimal risk profile will have their radiotherapy planned according to standard protocol. Participants assigned to the increased risk profile will have their radiotherapy planned using stricter, standardised guidelines. These guidelines will create consistency in HNC radiotherapy planning and include the following: - the planning radiotherapist will be responsible for defining audiology structures using the validated, audiology contouring atlas, developed and validated in phase one. This will ensure standardisation in the accuracy of contours. All contours will be checked for accuracy by the prescribing Radiation Oncologist. - a standardised ear radiation dose tolerance will be prescribed by the Radiation Oncologist. Currently, due to a lack of evidence based literature, ear tolerances vary greatly between physicians as it’s subject to physician preference. These tolerances were derived using information gathered in phase one, in conjunction with literature and oncologist clinical experience. It is important to note, that achieving these tolerances will not take priority over tumour coverage. Further, if a tighter dose tolerance is favourable, this is acceptable. In addition, all participants will undergo audiology testing. Current practice sees patients referred for audiology assessment when they complain of hearing loss. For this study, patients will undergo audiology assessment at four pre-determined time intervals throughout their treatment (before treatment, week 5 of treatment, 6-12 weeks and 1 year after treatment). Each session will last for approximately 45 minutes in pure tone audiometry, otoacoustic emissions testing, reflexometry and tympannometry testing will be carried out using beeps, whistle and word repetition. Two questionnaires will also be provided for completion at each of the follow up examinations and will take approximately 15 minutes to complete.. The outcomes of these questionnaires will enable the comparison of subjective and objective hearing results.