Voice evaluation before and after laser excision vs. Radiotherapy of t1a glottic carcinoma

Quality of voice after treatment for T1A glottic squamous cell carcinoma was studied in two matched groups of males treated either with CO₂ laser cordectomi (n = 18, mean age 65.2 years) or with full dose radiotherapy (n = 18, mean age 65.1 years). All patients had histologically verified invasive squamous cell carcinoma. Fifteen male patients (mean age 63.9 years) without laryngeal disorders were used as controls. Voice recordings prior to treatment, and both at 3 months and at 2 years after completed treatment were analyzed. Acoustic measures of shimmer, jitter, breathiness, harmonic-to-noise ratio and fundamental frequency (F0) average were calculated with the Soundscope program. Two plain measures were also used: time required to read a running speech voice sample, and number of breaths. Perceptual voice analysis was performed blindly by two groups of listeners, Group A (4 experienced listeners) and Group B (4 naive listeners). Group A estimated quality of voice according to a modified GRBAS score, whereas Group B estimated Grade only. We found voice quality both at 3 months and at 2 years after radiotherapy to be significantly better than after laser treatment, as assessed by the acoustic variables breathiness, jitter, F0 average, running speech voice sample reading time and number of breaths. The perceptual variables Grade (Group A and B), Breathiness, Asthenia and Strain were also significantly better after radiotherapy.