Age-dependent treatment effect of vocal fold steroid injection for benign vocal fold lesions.

Objective: Benign vocal fold lesions (BVFLs) cause voice disorders and impair social life. Recently, office-based vocal fold steroid injection (VFSI) has gained attention as a minimally invasive treatment for BVFLs. This study aimed to analyze the age-dependent treatment effect of VFSI and to clarify the indications for treatment. Methods: In this retrospective cohort study, a total of 83 patients with BVFLs were treated with a similar regimen of VFSI. Three or four months after the injection, age-dependent phonological functions were evaluated. The differences between pre- and post-treatment findings were analyzed using the Wilcoxon matched-pair signed-rank test, and the correlation between patient age and improvement rates were determined by Pearson's correlation coefficient. Results: Improvement in voice handicap index (VHI), which was the primary endpoint, was observed. Subjective and objective voice quality measurements also showed significant improvements. Subgroup analyses revealed that there was no age-related difference in the improvement of voice quality and that there was no improvement in aerodynamic effect in patients over 45 years of age. Conclusion: This study clarified the age-dependent treatment effect of VFSI and provided the important suggestion of establishing indication criteria for BVFLs. The study results provided clarity on the indication criteria of VFSI and served as an important indicator for tailoring treatment to patients' needs. Level of Evidence: 4.