The voice quality after laser surgery versus radiotherapy of T1a glottic carcinoma: systematic review and meta-analysis

Background and objectives: The voice quality assessment of laser surgery (LS) in comparison with radiotherapy (RT) remains uncertain in T1a glottic carcinoma treatment. This systematic review and meta-analysis were conducted to compare the voice quality of the two treatments. Methods: Searches were conducted in PubMed, EMBASE, and Cochrane with the following index words: glotti*, layn*, vocal cord, vocal, surgery, cordectomy, laser, radiation, irradiation, radiotherapy, cancer, and carcinoma for relative studies that compared the voice quality between LS and RT. Random-effect models were used, and heterogeneity was assessed. Results: A total of 14 studies were included in the analysis, consisting of 1 randomized controlled trial, 1 prospective study, and 12 retrospective studies. RT has increased the maximum phonation time (MPT; mean difference [MD] =-1.89, 95% confidence interval [CI] =-3.66 to -0.11, P=0.04) and decreased the fundamental frequency (MD =14.06, 95% CI =10.30-17.83, P<0.00001) in comparison with LS. No statistical difference was observed between the two groups in terms of Voice Handicap Index, Jitter, Shimmer, and airflow rate. Conclusion: RT may be a better choice for T1a glottic carcinoma treatment compared with LS because patients undergoing RT may have the advantage of increased MPT and decreased fundamental frequency. However, more multicenter, randomized, controlled trials are urgently needed to verify these differences.