CO₂ Laser Cordectomy Versus KTP Laser Tumor Ablation for Early Glottic Cancer: A Randomized Controlled Trial

Abstract

Background and ObjectivesCO2 laser cordectomy has been the workhorse of laser surgery for early glottic squamous cell carcinoma (GSCC) since the early 1970s. During the last decades, potassium titanyl phosphate (KTP) laser surgery for early GSCC gained popularity, introducing the tumor ablation technique. Yet, there are no previous randomized controlled trials (RCT) that compare the oncologic and functional outcomes of KTP Laser ablation versus CO2 laser cordectomy for early GSCC. This study aims to compare by means of an RCT, CO2 laser cordectomy with KTP laser ablation for early GSCC, in terms of cure rates and vocal function.Study Design/Materials and MethodsA RCT conducted between 2013 and 2017. Patients with early GSCC were enrolled, and randomly assigned for either CO2 cordectomy or KTP‐ablation surgery with curative intent. All CO2 cordectomies and most KTP‐ablation procedures were performed under general anesthesia. Some KTP cases with residual disease were treated also under local anesthesia. Videostroboscopy measures, voice handicap index (VHI), GRBAS (a hoarseness scale for Grade, Roughness, Breathiness, Asthenia and Strain) score, and acoustic analyses were performed pre‐operatively, 6 months and 3 years after surgery.ResultsTwenty‐four patients, 12 in each group, were enrolled. Nine in each group had T1a carcinoma, the remaining had either carcinoma in situ or T1b. The average number of procedures was 1.67( ± 0.89) and 1.33( ± 0.89) for the KTP and CO2 groups, respectively. Although the tumor depth was comparable in both groups, patients in the KTP‐ablation group underwent more superficial surgeries. Eleven (91.7%) procedures in the KTP group spared the vocal ligament, compared with 5 (41.7%) in the CO2 group, (P = 0.023). All patients were alive and disease‐free after four years. On post‐operative videostroboscopy, normal mucosal waves appeared in 5 (42%) of the KTP patients versus none (0%) of the CO2 (P = 0.02). The median post‐operative non‐vibrating portion was smaller in the KTP group (10%) compared with CO2 (50%), P = 0.043. Nevertheless, GRBAS and VHI scores improved comparably in both groups.ConclusionsKTP ablation technique offers similar curative outcome as CO2 cordectomy but may allow for better preservation of vocal fold's architecture and function. Yet, the clinical significance of these findings is unclear, since the subjective measures improved comparably for these two treatment modalities. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Outcomes of KTP Laser Ablation in Glottic Neoplasms: A Systematic Review and Meta‐Analysis

“…The final meta-analysis included eight studies (Figure 1). 6,[27][28][29][30][31][32][33] A total of 342 patients underwent KTP laser ablation within the included studies. All the included studies were performed between 2013 and 2022.…”

Voice After Cordectomy Type I or Type II or Radiation Therapy for Large T1a Glottic Cancer

“…The idea in TLM is to perform the most superficial and most narrow possible resection in order to preserve function 9,10 . The more superficial the resection, the better the patient's vocal function 10–12 .…”

“…The idea in TLM is to perform the most superficial and most narrow possible resection in order to preserve function. 9,10 The more superficial the resection, the better the patient's vocal function. [10][11][12] After TLM, long-term voice outcomes (6-24 months) were excellent after a subepithelial or subligamental cordectomy, [13][14][15] but after more extended surgeries, voice outcomes remained poor.…”

“…9,10 The more superficial the resection, the better the patient's vocal function. [10][11][12] After TLM, long-term voice outcomes (6-24 months) were excellent after a subepithelial or subligamental cordectomy, [13][14][15] but after more extended surgeries, voice outcomes remained poor. 15 In TLM, there is wound healing and scar formation on the ipsilateral vocal fold that concludes in 18 months.…”

Green‐light laser en bloc resection versus conventional transurethral resection for initial non‐muscle‐invasive bladder cancer: A randomized controlled trial

“…Compared with TURBt, en bloc resection with these lasers achieves high‐quality resection, which is reflected by the presence of DM in postoperative specimens 6 . Among the various laser types, the green laser operates at a wavelength of 532 nm, at which the energy is absorbed by HB, but not by water; 7 this laser causes little damage to the tissue during surgery, 8 and it also has comparable safety and effectiveness for NMIBC treatment to TURBt 9 . In the initial stage, however, only photoablation or vaporization techniques were applied for NMIBC with a green laser due to its high energy density (120 W).…”