Statistical analyses.
Statistical analysis of data was performed through Microsoft EXCEL and IBM SPSS statistics 25 software package Armonk, NY IBM corp. Comparisons between groups were performed using the χ2 test, ANOVA test (Bonferroni) and Kruskal-Wallis test for independent samples. An uninominal logistic regression analyses was performed to analyze if prognostic factor hearing loss at the end of treatment was a significant prognostic factor for late ototoxicity outcomes. The results were considered significant with a p-value < 0.05.