Comparison of BL and KTP Laser for Treatment of Benign Vocal Fold Lesions

Comparison of Treatment Outcome of Blue Light Laser and KTP Laser for Benign Vocal Fold Lesions: A Randomized Trial

Preliminary investigations suggest that a novel blue light (BL) laser with a wavelength of 445nm is comparable to the commonly utilized KTP laser (532nm) for treatment of laryngeal pathologies. An animal study by the Principal Investigators showed that the blue light laser results in significantly less vocal fold scarring compared to the KTP laser, suggesting that the blue light laser may be a better instrument for treating vocal fold disease. However, there are no clinical studies directly comparing the two lasers on treatment of vocal fold pathology. The goal of the proposed study is to directly compare treatment outcomes of the BL laser and KTP laser for benign vocal fold lesions. All laser treatments will be performed in the office under local anesthesia as per standard of care. Outcome variables of interest will be compared between groups, including Voice Handicap Index-10 (VHI-10) score (measured at baseline, 1 week, 1 month, and 3 months post procedure), laryngeal stroboscopic findings (1 and 3 months post procedure), and intra-operative pain. This study will provide support that the blue light laser is a comparable alternative to the KTP laser and allow the addition of this novel laser to the armamentarium for treating vocal fold diseases.

A novel blue light (BL) laser, TruBlue surgical laser, has recently been approved by Health Canada for use in the larynx. It has a wavelength of 445nm, which is within the same visible light spectrum as the KTP laser (532nm). It is a photoangiolytic laser like the KTP and can be delivered through a flexible fiber and therefore allowing the procedure to be performed in clinic under local anesthesia. Other advantages include better tissue cutting and increased portability. No clinical studies in the literature have directly compared the BL laser and KTP laser in the treatment of benign vocal fold lesions. The main objective of this proposal is to compare between-group differences in patient perception of voice handicap between BL laser and KTP laser for treatment of benign vocal fold lesions at 3 months compared to baseline. Given the PIs' previous work comparing vocal fold scarring induced by these two lasers in a rat model, we hypothesize that the blue light laser will be equally effective at treating benign vocal fold lesions as the KTP laser, resulting in improved VHI-10 score at 3 months post laser treatment compared to baseline.

The KTP laser has been a workhorse laser used in Otolaryngology/Laryngology for awake treatments of vocal fold lesions. However, it is phasing out of the market as the laser itself as well as the laser fibers compatible with this laser are no longer being manufactured. Therefore, Laryngologists are eagerly looking for an alternative to the KTP laser in order to fill this gap in care. The BL laser is cheaper in costs and more portable compared to the KTP. It also has better tissue cutting abilities which can be useful in treating certain vocal fold lesions such as vocal fold cancer and subglottic stenosis. This study is the first to directly compare treatment outcomes between the BL laser and KTP laser for vocal fold lesions. If the BL laser is shown to be comparable to the KTP in this clinical study, it lends support that this novel laser is indeed an excellent alternative to the KTP laser and can therefore be incorporated into routine patient care.

Inclusion Criteria:

1. Provision of signed and dated informed consent form;
2. Stated willingness to comply with all study procedures and availability for the duration of the study;
3. Male and female, aged ≥ 18 years; and
4. Diagnosed with benign vocal fold lesions such as papillomas and polyps and who are candidates for elective in office laser treatment for these lesions.

Exclusion Criteria:

1. < 18 years old;
2. Current smokers;
3. Vocal fold lesions such as vocal fold leukoplakia and vocal fold cancer;
4. Systemic steroid use; and
5. History of systemic illness that can affect wound healing.