Voice outcomes following radiation versus laser microsurgery for T1 glottic carcinoma: Systematic review and meta-analysis

Objective. Systematic review of literature on patient-reported voice handicap following T1 glottic squamous cell carcinoma treatment using transoral laser microsurgery or radiation therapy. Data Sources. PubMed, Web of Science, and Scopus (1997- 2013). Review Methods. These data sources were searched for papers reporting Voice Handicap Index (VHI) after treatment of early glottic carcinoma. Review and reference crosschecking were performed using a priori selection criteria. Study data were abstracted and publication quality categorized independently by 2 authors. Corresponding authors were contacted to maximize data for analysis. Meta-analysis was performed only with studies that included both treatment modalities, to reduce heterogeneity and maximize rigor; random effects modeling was used to pool results. Results. Eighteen publications were identified that reported VHI data following surgery and radiotherapy for T1 glottic carcinoma. No studies were randomized. When studies that reported multiple T-stages or systematic treatment selection bias were excluded, 8 retrospective cohort studies describing 362 patients were suitable for meta-analysis. Follow-up time (mean, 47 months; range, 1-298 mo) and extent of surgical excision varied across studies. Six studies showed no VHI difference between treatment arms; 2 favored radiotherapy over surgery (1 of which reported transmuscular cordectomy for all surgical patients); and none favored surgery. Meta-analysis showed no significant difference in posttreatment VHI between radiotherapy and surgery (mean difference, -5.52; 95% confidence interval, -11.40, 0.36; heterogeneity I2 = 61%, P = .01). Conclusion. VHI scores were comparable following transoral laser microsurgery and radiation therapy for T1 glottic carcinoma in the current literature, suggesting no clinically significant difference in functional voice outcomes between treatment types.