Quality of voice after radiotherapy in early vocal cord cancer

Change in Voice Quality after Radiotherapy for Early Glottic Cancer

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 (F0, 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.

Factors affecting voice quality in early glottic cancer before and after radiotherapy

Background

Radiotherapy (RT) is a successful mode of treatment for early glottic cancer. The aim of the study was to assess voice quality both before and 3 months after successful RT using multimodal methods while also identifying the factors affecting it.

Patients and methods

In 50 patients with T1 glottic carcinoma, the subjective (patients’ assessment of voice quality [VAS], Voice Handicap Index [VHI] questionnaire, phoniatricians’ assessment using the grade/roughness/ breathiness [GRB] scale), and objective assessments (fundamental laryngeal frequency [F₀]_, jitter, shimmer, maximum phonation time [MPT]) of voice quality were performed before RT and 3 months post-RT. The data on gender, age, extent of the tumors, biopsy types, smoking, local findings, and RT were obtained from the medical documentation.

Results

Three months after the treatment, VAS, VHI, G and R scores, F₀, and MPT significantly improved in comparison with their assessment prior to treatment. Before the treatment, the involvement of the anterior commissure significantly deteriorated jitter (p = 0.044) and the involvement of both vocal folds deteriorated jitter (p = 0.003) and shimmer (p = 0.007). After the RT, F₀ was significantly higher in the patients with repeated biopsy than in the others (p = 0.047). In patients with post-RT changes, the B score was significantly higher than in those without post-RT changes (p = 0.029).

Conclusions

Voice quality already significantly improved three months after the treatment of glottic cancer. The main reason for the decreased voice quality prior to treatment is the tumor’s extent. Post-RT laryngeal changes and repeated biopsies caused more scarring on vocal folds adversely influencing voice quality after the treatment.

Radiation fibrosis of the vocal fold: from man to mouse

OBJECTIVES/HYPOTHESIS

To characterize fundamental late tissue effects in the human vocal fold following radiation therapy. To develop a murine model of radiation fibrosis in order to ultimately develop both treatment and prevention paradigms.

DESIGN

Translational study using archived human and fresh murine irradiated vocal fold tissue.

METHODS

1) Irradiated vocal fold tissue from patients undergoing laryngectomy for loss of function from radiation fibrosis was identified from pathology archives. Histomorphometry, immunohistochemistry, and whole-genome microarray, as well as real-time transcriptional analyses, were performed. 2) Focused radiation to the head and neck was delivered to mice in a survival fashion. One month following radiation, vocal fold tissue was analyzed with histomorphometry, immunohistochemistry, and real-time PCR transcriptional analysis for selected markers of fibrosis.

RESULTS

Human irradiated vocal folds demonstrated increased collagen transcription, with increased deposition and disorganization of collagen in both the thyroarytenoid muscle and the superficial lamina propria. Fibronectin were increased in the superficial lamina propria. Laminin decreased in the thyroarytenoid muscle. Whole genome microarray analysis demonstrated increased transcription of markers for fibrosis, oxidative stress, inflammation, glycosaminoglycan production, and apoptosis. Irradiated murine vocal folds demonstrated increases in collagen and fibronectin transcription and deposition in the lamina propria. Transforming growth factor (TGF)-β increased in the lamina propria.

CONCLUSION

Human irradiated vocal folds demonstrate molecular changes leading to fibrosis that underlie loss of vocal fold pliability occurring in patients following laryngeal irradiation. The irradiated murine tissue demonstrates similar findings, and this mouse model may have utility in creating prevention and treatment strategies for vocal fold radiation fibrosis.