The oncological outcomes of transoral laser microsurgery (TOLM) for early laryngeal cancers are well-known to be very similar to radiation therapy (RT). The functional outcomes associated with each treatment modality are therefore of significant interest. This study is reported to be the first to look at long-term voice outcomes (greater than four years following treatment) in a cohort of 102 patients treated for early laryngeal cancer (CIS, T1 and T2), 55 of whom received TOLM and 47 of whom were treated with RT. The distribution of cancer stages was similar in both groups. Voice outcomes were assessed both subjectively via the Voice Handicap Index (VHI-10) scale and objectively, via software analysis of recorded voice samples to generate a Cepstral Spectral Index of Dysphonia (CSID) score, as well as via perceptual rating by two blinded speech pathologists using the GRBAS scale. No significant differences were noted in the mean VHI scores between the two treatment groups in the long term.
Both the CSID scores and the majority of the GRBAS scale ratings were, however, significantly better in the TOLM group as compared to the RT group. The mean CSID score was 28.9 in the TOLM group, versus 42.6 in the RT group (p <0.001).
Grade, roughness and strain scores were also significantly lower in the TOLM group. It is speculated that the reason for the apparently better objective voice outcomes for TOLM in the longer term is because of progressive fibrosis following radiotherapy, in contrast to the healing after TOLM which is considered to be complete at approximately 18 months. There are of course limitations to this study, not least of which is the lack of randomisation and consequent potential for selection bias. Patients in the RT group were also older on average that those in the TOLM group. Nevertheless, this study does provide useful preliminary data that can help counsel patients when it comes to selecting a treatment for an early laryngeal cancer that could be managed with either TOLM or RT.