Abstract
This study aims to report the incidence of adverse cochlear effects when treating patients of HNSCC with different radiation techniques and to compare the effect of different treatment modalities on the cochlea. This prospective observational study took place in a tertiary care centre, of 132 individual ears from 66 patients of HNSCC treated with conventional RT (group-1), IMRT (group-2), conventional RT with chemotherapy (group-3) and IMRT in combination with chemotherapy (group-4). Pure tone audiometry was performed during the follow-up period at 3 months and 1 year of completion of therapy. Correlation of audiometric change of both the ears at high frequencies (pure tone average 4 kHz, 6 kHz, 8 kHz), low frequencies (pure tone average 0.5-2 kHz) and BC (average 500-4 kHz) with series of factors were analyzed. There was a significant deterioration of hearing threshold 1 year after complete treatment, in all groups. There was an average drop in BC (0-1 year) by 19.63 ± 31.25% in group-2, 24.57 ± 21.96% in group-1 and a drop of 36.48 ± 43.97% and 70.78 ± 21.11% in group-3 and group-4 respectively. When we compared the audiometric change (PTAv at high and low frequency) from 0 to 1 year of group-1&2 the p value was significant (p = 0.050 at high frequency, p = 0.040 at low frequency). The audiological outcome of the different treatment modalities when compared, it was observed that the maximum hearing loss was in group-4 (IMRT with Chemotherapy) followed by group-3 (RTCT), group-1 (Conventional RT) and group-2 (IMRT).