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The choice of chromogen and reliability of contact rhinoscopy in the irradiated nasopharynx

Published online by Cambridge University Press:  04 January 2007

Martin W Pak*
Affiliation:
Division of Otorhinolaryngology, Department of Surgery, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, SARChina
Samuel Chow
Affiliation:
Division of Otorhinolaryngology, Department of Surgery, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, SARChina
C A van Hasselt
Affiliation:
Division of Otorhinolaryngology, Department of Surgery, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, SARChina
*
Address for correspondence: Professor Charles Andrew van Hasselt, Division of Otorhinolaryngology, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, 30–32 Ngan Shing Street, Shatin, New Territories, Hong Kong, SAR, China. Fax: (852) 2646 6312 E-mail: [email protected]

Abstract

A cross-sectional randomised single blind study was conducted to assess how concentrations of chromogen (vital stain) and the characteristics of the assessors affect the assessment of contact rhinoscopy. Twenty-eight patients who had undergone external radiotherapy for nasopharyngeal carcinoma were assessed by contact rhinoscopy using 0.5 per cent and 1 per cent methylene blue stain on opposite sides of the nasopharynx. Three independent observers assessed the visual clarity of the 45 contact endoscopic images showing squamous metaplasia according to a visual analogue scale. The intraclass correlation coefficients were 0.916 to 0.957 and 0.839 to 0.964 for intra-observer reliability of assessors in the groups of 0.5 per cent and 1 per cent stains, respectively. The intraclass correlation coefficients for inter-observer reliability of assessors were 0.884 and 0.885 in the groups of 0.5 per cent and 1 per cent stains, respectively. The mean scores of clarity of the cellular details were statistically higher in the group of 1 per cent stain among all assessors. These results showed that the assessment of squamous metaplasia by contact endoscopy is highly reliable irrespective of the clinical experience and knowledge of histopathology of the assessors. One per cent methylene blue should be the vital stain of choice in contact endoscopy.

Type
Main Articles
Copyright
Copyright © JLO (1984) Limited 2006

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References

1 Hamou, JE. Microendoscopy and contact endoscopy. Brevet Francais 79,04168, Paris 1979. International Patent PCT/FR80/0024, Paris 1980. US Patent 4,385,810, Washington, DC, 1983Google Scholar
2 Hamou, JE. Microhysteroscopy – A new technique in endoscopy and its applications. Acta Endoscopica 1980;10:415–22CrossRefGoogle Scholar
3 Andrea, M, Dias, O, Santos, A. Contact endoscopy of the vocal cord: normal and pathological patterns. Acta Otolaryngol (Stockh) 1995;115:314–16Google Scholar
4 Pak, MW, To, KF, Leung, SF, van Hasselt, CA. In vivo diagnosis of nasopharyngeal carcinoma using contact rhinoscopy. Laryngoscope 2001;111:1453–8Google Scholar
5 Pak, MW, To, KF, Leung, SF, van Hasselt, CA. In vivo diagnosis of persistent and recurrent nasopharyngeal carcinoma by contact endoscopy. Laryngoscope 2002;112:1459–66CrossRefGoogle ScholarPubMed
6 Pak, MW, Lee, JCK, Liang, EY, van Hasselt, CA. In vivo real-time diagnosis of nasopharyngeal carcinoma-in-situ (NPCIS) by contact rhinoscopy. Head & Neck 2005;27:1008–13Google Scholar
7 Shiozaki, H, Tahara, H, Kobayashi, K, Yano, H, Tamura, S, Imamoto, H et al. Endoscopic screening of early esophageal cancer with the Lugol dye method in patients with head and neck cancers. Cancer 1990;66:2068–713.0.CO;2-W>CrossRefGoogle ScholarPubMed
8 Canto, MI, Setrakian, S, Petras, RE, Blades, E, Chak, A, Sivak, MV Jr et al. Methylene blue selectively stains intestinal metaplasia in Barrett's esophagus. Gastrointest Endosc 1996;44:17Google Scholar
9 Morikawa, F, Fukuda, M, Naganuma, M, Nakayama, Y. Phototoxic reaction to xanthene dyes induced by visible light. J Dermato 1976;3:5967CrossRefGoogle ScholarPubMed
10 Misumi, A, Harada, K, Murakami, A, Arima, K, Kondo, H, Akagi, M et al. Role of Lugol dye endoscopy in diagnosis of early esophageal cancer. Endoscopy 1990;22:1216CrossRefGoogle ScholarPubMed
11 Seitz, JF, Monges, G, Navarro, P, Giovannini, M, Gauthier, A. Endoscopic detection of dysplasia and subclinical cancer of esophagus: results of a prospective study using toluidine blue vital staining in 100 patients with alcoholism and smoking. Gastroenterol Clin Biol 1990;14:1521Google Scholar
12 Andrea, M, Dias, O. Contact endoscopy- technical requirements. In: Contact Endoscopy of the Upper Aerodigestive Tract. Tuttlingen: Endo-Press, 1999;69Google Scholar
13 Wardrop, PJC, Sim, S, McLaren, K. Contact endoscopy of the larynx: a quantitative study. J Laryngol Otol 2000;114:437–40CrossRefGoogle ScholarPubMed
14 Chang, AR, Chan, MKM. Cytological Diagnosis. In: van Hasselt, CA, Gibb, AG, eds. Nasopharyngeal Carcinoma, 2nd edn. Hong Kong: The Chinese University Press, 1999;177–93Google Scholar