Publications [#172250] of Gregory M Palmer

Papers Published

1. GM Palmer, C Zhu, TM Breslin, F Xu, KW Gilchrist, N Ramanujam, Comparison of multiexcitation fluorescence and diffuse reflectance spectroscopy for the diagnosis of breast cancer (March 2003)., IEEE transactions on bio-medical engineering, vol. 50 no. 11 (November, 2003), pp. 1233-42, ISSN 0018-9294 [doi]
   (last updated on 2013/07/01)

   Abstract:
   Nonmalignant (n = 36) and malignant (n = 20) tissue samples were obtained from breast cancer and breast reduction surgeries. These tissues were characterized using multiple excitation wavelength fluorescence spectroscopy and diffuse reflectance spectroscopy in the ultraviolet-visible wavelength range, immediately after excision. Spectra were then analyzed using principal component analysis (PCA) as a data reduction technique. PCA was performed on each fluorescence spectrum, as well as on the diffuse reflectance spectrum individually, to establish a set of principal components for each spectrum. A Wilcoxon rank-sum test was used to determine which principal components show statistically significant differences between malignant and nonmalignant tissues. Finally, a support vector machine (SVM) algorithm was utilized to classify the samples based on the diagnostically useful principal components. Cross-validation of this nonparametric algorithm was carried out to determine its classification accuracy in an unbiased manner. Multiexcitation fluorescence spectroscopy was successful in discriminating malignant and nonmalignant tissues, with a sensitivity and specificity of 70% and 92%, respectively. The sensitivity (30%) and specificity (78%) of diffuse reflectance spectroscopy alone was significantly lower. Combining fluorescence and diffuse reflectance spectra did not improve the classification accuracy of an algorithm based on fluorescence spectra alone. The fluorescence excitation-emission wavelengths identified as being diagnostic from the PCA-SVM algorithm suggest that the important fluorophores for breast cancer diagnosis are most likely tryptophan, NAD(P)H and flavoproteins.

   Keywords:
   Algorithms* • Breast Neoplasms • Diagnosis, Computer-Assisted • Humans • Pattern Recognition, Automated • Predictive Value of Tests • Principal Component Analysis • Reproducibility of Results • Sensitivity and Specificity • Spectrometry, Fluorescence • Spectrophotometry, Ultraviolet • classification* • diagnosis* • methods* • pathology