Voice Outcomes after Radiotherapy Treatment for Early Glottic Cancer: Long-Term Follow-Up.

ABSTRACT

OBJECTIVES: The aim of this study was to investigate long-term voice outcomes and voice-related quality of life (QOL) for early glottic cancer treated with radiotherapy. STUDY DESIGN: Long-term exploratory follow-up study of a prospective patient cohort comparing outcomes at a mean of 11 years postradiotherapy with the original 1-year posttreatment results. METHOD: Eight patients completed voice tasks for auditory perception and acoustic and aerodynamic measures. Patient-reported voice-related QOL (VR-QOL) and voice quality were measured. Changes in outcomes over time were analysed using repeated-measures linear mixed models. RESULTS: Acoustic and aerodynamic outcomes remained stable from 1 year postradiotherapy to long-term follow-up, with only jitter mildly increasing from 1.9% at 1 year posttreatment to 2.8% (difference = 1.0%, 95% confidence interval [CI] = 0.1-1.9). Perceptually, voice remained relatively stable with only phonation breaks slightly increasing within the normal range, from 1.1 to 1.7 (difference = 0.6, 95% CI = 0.3-0.9) and breathy quality increasing from normal to slight impairment, with scores increasing from 1.8 to 2.4 (difference = 0.6, 95% CI = 0.3-1.1). QOL scores indicate a good level of VR-QOL that were unchanged at long-term follow-up when compared with 1 year posttreatment. CONCLUSIONS: Improvement in voice outcomes found at 1 year postradiotherapy were largely maintained long term, with only minor changes observed. QOL scores indicate that a high level of VR-QOL was maintained many years after curative radiotherapy.