TLM for glottic carcinoma has historically been performed with a carbon dioxide (CO2) laser. A much smaller literature base has examined the use of potassium titanyl phosphate (KTP) laser in this context. This retrospective chart review aims to fill that gap. It reports on 87 patients treated over five years for T1a or T1b squamous cell carcinoma of the glottis. Treatment consisted of either primary external beam radiation therapy (40 patients) or KTP-TLM (47 patients). They state that where suitable a choice of either treatment was offered to all patients. There were no significant differences between the two treatment groups in proportion of T1a and T1b disease and presence of anterior commissure involvement. There were similar rates of recurrence in the two groups.
The laryngeal preservation rate for the cohort of patients who initially received KTP laser treatment was 46 out of 47 patients and was 36 out of 40 patients in the radiation group (p = 0.18). Disease-free and overall survival were 88% and 98% in the KTP laser cohort and 85% and 95% in the radiation cohort.
From this we can tentatively accept the conclusion that KTP laser ablation is a modality equivalent to primary radiation therapy in oncologic outcomes for T1 glottic squamous cell carcinoma. However, in choosing one modality over the other voice outcomes are often a critical factor.
Objective voice assessments were carried out pre- and postoperatively in 21 of the surgically treated patients showing a significant decrease in shimmer, jitter, and noise-to-harmonic ratio. VHI assessment in 11 of the surgical patients showed a significant trend towards improvement.
This is all very promising. However, this study has reported these outcomes in only a proportion of the surgical cohort and unfortunately has not addressed this at all in the radiation arm.