Background and objectives: Transoral laser surgery is the optimal surgical treatment modality for the early stages of glottic cancer. To allow for further treatment to be as effective and as minimal as possible, persistent or recurrent tumors should be detected very soon. The main aim is to minimize the risk of necessity of performing a total laryngectomy. Flexible videoendoscopy with narrow band imaging (NBI) was recommended by the European Laryngological Society as a diagnostic method for the follow-up of patients treated for laryngeal cancer. Nevertheless, the efficacy of this technique has not been extensively studied in patients after transoral laser cordectomies for vocal fold cancer. The aim of this study was to evaluate the efficacy of in-office transnasal NBI flexible videoendoscopy in the follow-up of patients after transoral laser cordectomy for glottic cancer. We also focused on describing the specific characteristics of recurrent tumor appearance.
Materials and methods: The presented study was conceived as a prospective study. Ninety-four consecutive patients who underwent transoral laser cordectomy for severe dysplasia, Tis, T1, and T2 glottic cancer in the period from June 2010 to August 2015 were enrolled in the study. All patients were postoperatively regularly followed using transnasal videoendoscopic examinations with NBI. Whenever a suspect lesion was identified during in-office examination, its nature was proven histologically.
Results: We discovered 23 suspect findings in 21 patients by means of flexible videoendoscopy with NBI. Fifteen (65.2%) of them were histologically confirmed as recurrent tumors, whereas in 8 (34.8%) of them, the recurrent tumor was not proven. In two patients, the recurrent tumor was evident on computed tomography or magnetic resonance imaging, but NBI endoscopy did not reveal relapsing disease. The rest (71 patients) were considered true negative. Of the 15 recurrent tumors detected by NBI-coupled videoendoscopy, 8 (53.3%) were identified as submucosal masses with nonsignificant or no vascular changes, 4 (26.7%) were noted as the progression of leukoplakia without visible vascular changes, only 2 (13.3%) showed typical vascular changes, and, in 1 (6.7%) case, evident, significantly exophytic tumor with pathological vascularization was discovered. The sensitivity, specificity, and positive and negative predictive values of the in-office transnasal videolaryngoscopy with NBI were calculated to be 88%, 92%, 71%, and 97%, respectively.
Conclusions: The results of the study demonstrate that transnasal endoscopy with NBI in an outpatient setting is an excellent method for the follow-up of patients after transoral laser cordectomy for glottic cancer. The method achieves high sensitivity, specificity, and negative predictive value and a slightly low positive predictive value. Nevertheless, we must bear in mind that recurrent tumors after previous endoscopic resection may have a completely different appearance than new tumors originating from previously untreated tissues. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.
Keywords: laryngeal cancer; laryngeal endoscopy; narrow band imaging; transoral laser surgery.
© 2019 Wiley Periodicals, Inc.