Comparative Assessment on Laryngeal Function after Radiotherapy and Laser Surgery against Early Glottic Cancer

Abstract

Objectives: Comparatively assess the laryngeal function and quality of life (QOL) of the patients after laser surgery and radiotherapy against early glottic cancer. Methods: Sixty-seven patients with T1 glottic cancer treated in our institution with radiotherapy (RT, n=30) or CO2 laser surgery (LS, n=37) were incorporated in this retrospective cohort study. LSs were performed following the type II subligamental cordectomy concept. Patients in LS group were categorized into subgroups for further analyses. Twenty-seven patients had vaporization of the lesion with defocused mode, and a residual 10 patients had cancer excision with focused mode using relatively lower power (LS-EX group). GRBAS subjective voice assessment scale, maximum phonation time, and acoustic parameters were measured as vocal parameters. Voice-Related Quality of Life Measure and Voice Handicap Index were used to evaluate post-therapeutic QOL. Laryngeal videostroboscopic images were further examined to assess post-therapeutic laryngeal pliability. The mean follow-up period was 46 months. Results: Compared with their pre-therapeutic scores, worse GRBAS scores were observed at the end of the treatments in 20% and 60% of RT group and LS group respectively. Although these scores recovered 1 year after treatment, abnormal stroboscopic findings remained in 40% and 95% of RT group and LS group respectively. Interestingly, further subgroup analysis proved no significant difference of post-therapeutic vocal parameters and QOL between RT group and LS-EX group. Conclusions: Early glottic cancer could be treated with equivalent post-therapeutic laryngeal function and QOL with either radiotherapy or focused low power CO2 laser surgery.