Exclusive Radiotherapy for Early-stage Glottic Cancer: A Single-institution Retrospective Analysis with a Focus on Voice Quality

Abstract

Aim: To report on clinical outcomes of patients with early-stage glottic cancer treated with exclusive radiotherapy with specific analysis of voice quality.

Patients and methods: A consecutive cohort of 55 patients with early glottic cancer was retrospectively analyzed. Patients were treated with exclusive radiation up to a conventionally fractionated total dose of 66-70 Gy with a 3-dimensional conformal technique. Oncological outcomes and toxicity profiles were investigated. A sub-sample of this cohort was also analyzed in terms of voice quality employing subjective and objective tools such as the Voice Handicap Index-10 (VHI-10) and the Multidimensional Voice Program (MDVP™) software and was compared to a group of similar patients treated with CO2 laser cordectomy.

Results: after a median observation time of 74.5 months, 5- and 10-year local control was 89% [95% confidence interval (CI)=70.7-93.1%] and 86% (95% CI=68.7-89.6%), respectively. Larynx-preservation rate was 91.8% (95% CI=82.4%-94.9%) at 10 years. Five- and 10-year actuarial overall survival was 72% (95% CI=50.4-79.2%) and 56% (95% CI=48.7-64.3%). Maximum detected acute toxicity included G3 dermatitis (5.4%) and G4 dyspnea (1.8%). Late toxicity profile was mild. VHI-10 scores showed a mild voice disability in both groups, with no statistically significant difference (p=0.12), even when investigating different domains. Patients treated with radiation had a lower deterioration rate in all parameters excluding low voice, interruptions of sound and diplophony.

Conclusion: Exclusive radiation proved an effective treatment for patients with early glottic cancer in terms of both oncological outcome and voice quality.

Keywords: Glottic cancer; radiotherapy; voice quality.