HSC Section 6 Nov2016 Green Book

Vojko Djukic, et al

Stroboscopy in Detection of Laryngeal Dysplasia

of the mucosal wave, whereas digital kymography can be used to provide a complete three-dimensional profile of vocal fold vibration dynamics. 23,24 Although these new techniques are superior to stroboscopy, there are some limitations to their use. High-speed imaging systems are still too expensive to be widely used in clinical practice, gathering larger data sets is problematic because of that fact, and there are no general ac- cepted clinical protocols in laryngology for these techniques. 25 After performing the multivariate regression analysis, some factors, such as the type of cordectomy and the existence of a nonvibrating segment, were set apart from others and were proven to significantly correlate with various levels of dysplasia ( P < 0.05). However, after logistic regression of all chosen fac- tors (ie, cordectomy type and stroboscopic signs—glottic occlu- sion, phase symmetry, periodicity, amplitude of vibrations, mucosal wave, and nonvibrating segment), only the abnormal amplitude of vocal fold vibrations was observed to occur signif- icantly more frequently for recurrent disease in the group with mild dysplasia and in all patients. None of the factors was signif- icant for disease progression. The presence of some factors placed the patients at higher risk of recurrence and progression of the disease. The patient group with mild dysplasia and abnor- mal vocal fold vibration amplitudes had a 2.93 times greater risk of recurrence, and the group with nonvibrating segments was at 4.62 times greater risk compared with patients without those stroboscopic signs. Nonvibrating segment placed those patients at a 7.17 times greater risk of disease progression than those patients without nonvibrating segment during stroboscopic examination. In the group with moderate dysplasia, patients with insufficient glottic occlusion and abnormal amplitude of vocal fold vibrations were at a greater risk of recurrence. In that group, the patients with insufficient glottic occlusion, with abnormal amplitude of vocal fold vibrations, and the existence of nonvibrating segment were at a greater risk of disease pro- gression. In the patient group with severe dysplasia, the greater risk of recurrence and disease progression aligned with the type of cordectomy and abnormal amplitude of vocal fold vibrations. These findings could also be the result of a relatively small number of patients in the different dysplasia groups, which is one of the limitations of this study. With a larger number of pa- tients, some of the stroboscopic signs could be more prominent. Chang et al 26 conducted a study on a small (18 patients) and nonhomogenous group of patients with laryngeal dysplasia and carcinoma to determine whether the clinical features and clinical appearance of the lesions at presentation correlated with the outcomes of treatment in terms of cure rate and voice outcome. They noted that the clinical appearance of the lesion at presentation, as judged by either still light endoscopy or stro- boscopy, did not correlate with disease recurrence. The lesion appearance on still light endoscopy and vibratory characteristics on stroboscopy also did not correlate with the disease-free inter- val or voice outcome after endoscopic resection. Stroboscopy is a subjective method in terms of a stroboscopic parameter rating system, and the person conducting the proce- dure should be well trained to reduce variation and bias. Be- cause of the increasing popularity of stroboscopy equipment in the general otolaryngology office, it is useful to point out

some limitations of stroboscopy that can benefit less experi- enced examiner. In this article, we showed that a large and clin- ically significant number of cases with CIS with absence of nonvibrating segments can be overlooked when relying solely on stroboscopy. Caution must be exercised when assessing stroboscopic findings, particularly during the posttreatment follow-up period, or if other more sophisticated means of diagnostics are unavailable. CONCLUSION Stroboscopy cannot be used reliably for classifying laryngeal dys- plasia. Some stroboscopic signs cannot be used as an indication for performing or not performing laryngomicroscopy with biopsy in cases of any suspicious vocal fold lesions. In the absence of more expensive and advanced diagnostic methods, vocal fold dys- plasia could be precisely classified only by histopathology analy- sis. The patient age, treatment modality, and stroboscopic signs, such as abnormal amplitude of vocal fold vibration and the exis- tence of nonvibrating segment, can be considered as warning fac- tors for recurrence and disease progression. REFERENCES 1. Gallo A, De Vincentiis M, Della Rocca C, Moi R, Simonelli M, Minni A, Shaha AR. Evolution of precancerous laryngeal lesions: a clinicopatholog- ical study with long-term follow-up on 259 patients. Head Neck . 2001;23: 42–47 . 2. Ricci G, Molini E, Faralli M, Simoncelli C. Retrospective study on precan- cerous laryngeal lesions: long-term follow-up. Acta Otorhinolaryngol Ital . 2003;23:362–367 . 3. Isenberg JS, Crozier DL, Dailey SH. Institutional and comprehensive re- view of laryngeal leukoplakia. Ann Otol Rhinol Laryngol . 2008;117:74–79 . 4. Shanmugaratnam K, Sobin LH. The World Health Organization histologi- cal classification of tumours of the upper respiratory tract and ear. A com- mentary on the second edition. Cancer . 1993;71:2689–2697 . 5. Bosman FT. Dysplasia classification: pathology in disgrace? J Pathol . 2001;194:143–144 . 6. Hirano M, Bless DM. Videostroboscopic Examination of the Larynx . San Diego, CA: Singular Publishing Group Inc; 1993 . 7. Kelley RT, Colton RH, Casper J, Paseman A, Brewer D. Evaluation of stro- boscopic signs. J Voice . 2011;25:490–495 . 8. Remacle M, Van Haverbeke C, Eckel H, Bradley P, Chevalier D, Djukic V, de Vicentiis M, Friedrich G, Olofsson J, Peretti G, Quer M, Werner J. Pro- posal for revision of the European Laryngological Society classification of endoscopic cordectomies. Eur Arch Otorhinolaryngol . 2007;264:499–504 . 9. Dispenza F, De Stefano A, Marchese D, Martines F, Dispenza C. Management of laryngeal precancerous lesions. Auris Nasus Larynx . 2012;39:280–283 . 10. Montgomery J, White A. A decade of laryngeal dysplasia in Paisley, Scotland. Eur Arch Otorhinolaryngol . 2012;269:947–951 . 11. Spielmann PM, Palmer T, McClymont L. 15-Year review of laryngeal and oral dysplasias and progression to invasive carcinoma. Eur Arch Otorhino- laryngol . 2010;267:423–427 . 12. Weller M, Nankivell P, McConckey C, Paleri V, Mehanna M. The risk and interval to malignancy of patients with laryngeal dysplasia: a systematic re- view of case series and meta-analysis. Clin Otolaryngol . 2010;35:364–372 . 13. Gamboa J, Echeverrıa L, Molina B, Cobeta I. Stroboscopic assessment of chronic laryngitis. Acta Otorrinolaringol Esp . 2006;57:266–269 . 14. Arens C, Glanz H, W € onckhaus J, Hersemeyer K, Kraft M. Histologic as- sessment of epithelial thickness in early laryngeal cancer or precursor le- sions and its impact on endoscopic imaging. Eur Arch Otorhinolaryngol . 2007;264:645–649 . 15. Colden D, Jarboe J, Zeitels SM, Bunting G, Hillman RE, Spanou K. Stro- boscopic assessment of vocal fold keratosis and glottic cancer. Ann Otol Rhinol Laryngol . 2001;110:293–298 .

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