title: Optimal excitation wavelengths for discrimination of cervical neoplasia.
abstract: Fluorescence spectroscopy has shown promise for the in vivo, real-time detection of cervical neoplasia. However, selection of excitation wavelength has in the past been based on in vitro studies and the availability of light sources. The goal of this study was to determine optimal excitation wavelengths for in vivo detection of cervical neoplasia. Fluorescence excitation-emission matrices (EEMs) were measured in vivo from 351 sites in 146 patients. Data were analyzed in pairs of diagnostic classes to determine which combination of excitation wavelengths yields classification algorithms with the greatest sensitivity and specificity. We find that 330-340-, 350-380-, and 400-450-nm excitation yield the best performance. The sensitivity and specificity for discrimination of squamous normal tissue and high-grade squamous intraepithelial lesion (HGSIL) were 71% and 77% on cross validation using three excitation wavelengths. These results are comparable with those found in earlier in vivo studies; however, in this study we find that the proportion of samples which are HGSIL influences performance. Furthermore stratification of samples within low-grade squamous intraepithelial lesion and HGSIL also appears to influence diagnostic performance. Future diagnostic studies should be carried out at these excitation wavelengths in larger groups so that data can be stratified by diagnostic subcategory, age and menopausal status. Similarly, large studies should be done in screening populations.
authors.affiliation: Electrical and Computer Engineering Department, University of Texas at Austin, 78712, USA.
authors.forename: Sung K
authors.initials: SK
authors.lastname: Chang
authors.forename: Michele
authors.initials: M
authors.lastname: Follen
authors.forename: Anais
authors.initials: A
authors.lastname: Malpica
authors.forename: Urs
authors.initials: U
authors.lastname: Utzinger
authors.forename: Gregg
authors.initials: G
authors.lastname: Staerkel
authors.forename: Dennis
authors.initials: D
authors.lastname: Cox
authors.forename: E Neely
authors.initials: EN
authors.lastname: Atkinson
authors.forename: Calum
authors.initials: C
authors.lastname: MacAulay
authors.forename: Rebecca
authors.initials: R
authors.lastname: Richards-Kortum
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000473:pathology; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008856:Microscopy, Fluorescence / Q000295:instrumentation* / Q000379:methods; D030361:Papillomavirus Infections / Q000473:pathology; D025341:Principal Component Analysis; D011786:Quality Control; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D014412:Tumor Virus Infections / Q000473:pathology; D014466:Ultraviolet Rays; D002583:Uterine Cervical Neoplasms / Q000145:classification* / Q000473:pathology*; D014626:Vaginal Smears; D002578:Uterine Cervical Dysplasia / Q000473:pathology