title: Cervical precancer detection using a multivariate statistical algorithm based on laser-induced fluorescence spectra at multiple excitation wavelengths.
abstract: A portable fluorimeter was developed and utilized to acquire fluorescence spectra from 381 cervical sites in 95 patients at 337, 380 and 460 nm excitation immediately prior to colposcopy. A multivariate statistical algorithm was used to extract clinically useful information from tissue spectra acquired in vivo. Two full-parameter algorithms were developed using tissue fluorescence emission spectra at all three excitation wavelengths (161 excitation-emission wavelength pairs) for cervical precancer (squamous intraepithelial lesion [SIL]) detection: a screening algorithm that discriminates between SIL and non-SIL with a sensitivity of 82 +/- 1.4% and specificity of 68 +/- 0.0%, and a diagnostic algorithm that differentiates high-grade SIL from non-high-grade SIL with a sensitivity and specificity of 79 +/- 2% and 78 +/- 6%, respectively. Multivariate statistical analysis was also employed to reduce the number of fluorescence excitation-emission wavelength pairs needed to redevelop algorithms that demonstrate a minimum decrease in classification accuracy. Two reduced-parameter algorithms that employ fluorescence intensities at only 15 excitation-emission wavelength pairs were developed: the screening algorithm differentiates SIL from non-SIL with a sensitivity of 84 +/- 1.5% and specificity of 65 +/- 2% and the diagnostic algorithm discriminates high-grade SIL from non-high-grade SIL with a sensitivity and specificity of 78 +/- 0.7% and 74 +/- 2%, respectively. Both the full-parameter and reduced-parameter screening algorithms discriminate between SIL and non-SIL with a similar specificity (+/-5%) and a substantially improved sensitivity relative to Pap smear screening. A comparison of the full-parameter and reduced-parameter diagnostic algorithms to colposcopy in expert hands indicates that all three have a very similar sensitivity and specificity for differentiating high-grade SIL from non-high-grade SIL.
authors.affiliation: University of Texas, Austin 78712, USA.
authors.forename: N
authors.initials: N
authors.lastname: Ramanujam
authors.forename: M F
authors.initials: MF
authors.lastname: Mitchell
authors.forename: A
authors.initials: A
authors.lastname: Mahadevan-Jansen
authors.forename: S L
authors.initials: SL
authors.lastname: Thomsen
authors.forename: G
authors.initials: G
authors.lastname: Staerkel
authors.forename: A
authors.initials: A
authors.lastname: Malpica
authors.forename: T
authors.initials: T
authors.lastname: Wright
authors.forename: N
authors.initials: N
authors.lastname: Atkinson
authors.forename: R
authors.initials: R
authors.lastname: Richards-Kortum
mesh_terms: D000465:Algorithms; D005260:Female; D006801:Humans; D007834:Lasers; D015999:Multivariate Analysis; D011230:Precancerous Conditions / Q000175:diagnosis*; D013050:Spectrometry, Fluorescence; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis*; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis*