Consequences of voice impairment in daily life for patients following radiotherapy for early glottic cancer: voice quality, vocal function, and vocal performance

PURPOSE: To assess consequences of voice impairment in daily life for patients following radiotherapy for early glottic cancer, by means of a multidimensional analysis protocol including voice quality, vocal function, and vocal performance measures.

METHODS AND MATERIALS: A total of 60 men treated with radiotherapy (66 Gy/33 fractions, 60 Gy/30 fractions, 60 Gy/25 fractions) for early T1 glottic cancer and 20 matched control speakers filled in questionnaires on vocal performance. Furthermore, perceptual analyses of voice quality and stroboscopic measures of vocal function were performed. There was a longitudinal group of 10 patients from whom data were collected before, as well as 6 months and 2 years after, radiation. Furthermore, data were collected on 5 separate groups of 10 patients each: before, 6 months after, 2 years after, 3-7 years after, and 7-10 years after radiation.

RESULTS: High correlations were found between self-ratings of vocal performance and several voice measures. Patients before radiotherapy experienced poor voice characteristics that improved 6 months to 10 years after treatment, and became comparable to vocal performance of control speakers in 50% of the patients. Following radiotherapy, deviant voice characteristics and consequences in daily life occurred significantly more often for patients in whom initial diagnosis consisted of stripping the vocal cord instead of biopsies and for patients who continued smoking after treatment.

CONCLUSION: Voice characteristics of patients diagnosed with early glottic cancer improved after radiotherapy, and became normal in half of our patients. Stripping the vocal cord for initial diagnosis and continued smoking after treatment decreased deviant voice characteristics.