Change in Voice Quality after Radiotherapy for Early Glottic Cancer

SIMPLE SUMMARY: The voice of a patient is expected to improve after successful radiotherapy for early glottic cancer. The aim of this study was to follow the changes in the voice for two years after a completed treatment. Subjective patient and physician assessments of the voice quality and objective acoustic analyses of the voice of each patient were used to follow up on the voice changes at regular intervals in 50 patients with T1 glottic cancer. A stroboscopy showed the progression of radiotherapy-induced fibrosis of the vocal folds, which influenced their vibration during phonation. A subjective assessment of the voice quality showed a gradual improvement, but an objective measurement showed a deterioration in a few voice parameters. Two years after the treatment, only 16% of patients had normal voices. The main cause of the impaired voice quality was post-radiotherapy scarring of the vocal folds. ABSTRACT: Our aim was to track the changes in voice quality for two years after radiotherapy (RT) for early glottic cancer. A videoendostroboscopy, subjective patient and phoniatrician voice assessments, a Voice Handicap Index questionnaire, and objective acoustic measurements (F(0,) jitter, shimmer, maximal phonation time) were performed on 50 patients with T1 glottic carcinomas at 3, 12, and 24 months post-RT. The results were compared between the subsequent assessments, and between the assessments at 3 months and 24 months post-RT. The stroboscopy showed a gradual progression of fibrosis of the vocal folds with a significant difference apparent when the assessments at 3 months and 24 months were compared (p < 0.001). Almost all of the subjective assessments of voice quality showed an improvement during the first 2 years, but significant differences were noted at 24 months. Jitter and shimmer deteriorated in the first year after RT with a significant deterioration noticed between the sixth and twelfth months (p = 0.048 and p = 0.002, respectively). Two years after RT, only 8/50 (16%) patients had normal voices. The main reasons for a decreased voice quality after RT for early glottic cancer were post-RT changes in the larynx. Despite a significant improvement in the voice after RT shown in a few of the evaluation methods, only a minority of the patients had a normal voice two years post-RT.