Stokes shift spectroscopy pilot study for cancerous and normal prostate tissues

Abstract

Stokes shift spectroscopy (S3) is an emerging approach toward cancer detection. The goal of this paper is to evaluate the diagnostic potential of the S3 technique for the detection and characterization of normal and cancerous prostate tissues. Pairs of cancerous and normal prostate tissue samples were taken from each of eight patients. Stokes shift spectra were measured by simultaneously scanning both the excitation and emission wavelengths while keeping a fixed wavelength interval Δλ=20 nm between them. The salient features of this technique are the highly resolved emission peaks and significant spectral differences between the normal and cancerous prostate tissues, as observed in the wavelength region of 250 to 600 nm. The Stokes shift spectra of cancerous and normal prostate tissues revealed distinct peaks around 300, 345, 440, and 510 nm, which are attributed to tryptophan, collagen, NADH, and flavin, respectively. To quantify the spectral differences between the normal and cancerous prostate tissues, two spectral ratios were computed. The findings revealed that both ratio parameters R1=I297/I345 and R2=I307/I345 were excellent diagnostic ratio parameters giving 100% specificity and 100% sensitivity for distinguishing cancerous tissue from the normal tissue. Our results demonstrate that S3 is a sensitive and specific technique for detecting cancerous prostate tissue.

A technique for correction of attenuations in synchronous fluorescence spectroscopy

“…Selection of optimum wavelength offset and quality of SF signal in case of multiple fluorophores depend upon two parameters, namely resolution and magnitude [23,25]. On the basis of these two parameters smaller wavelength offsets are selected as optimum offset to study behavior of multiple components in biological samples [17,18,[20][21][22][23][24][25][28][29][30]. It is observed that our technique works efficiently for lower offsets for a wide-range of concentrations of scatterers and absorbers compared to larger one, consistent with the offsets reported in literature [17,18,[20][21][22][23][24][25][28][29][30].…”

“…Peuravuori et al used synchronous fluorescence spectroscopy for differentiating different humic-solute aggregates from water sample [16]. In recent years, it has been applied in cancer diagnosis [17][18][19][20][21][22][23][24][25][26][27][28][29]. Diagaradjane et al explored the potential of this technique to discriminate the sequential tissue transformation in DMBA-TPA induced tumor model in mouse skin [30].…”

“…Liu et al used this technique for multicomponent analysis in tissue [26]. Extensive studies have been performed by Alfano et al, to understand the mechanism of synchronous fluorescence spectroscopy in tissue samples at various offset wavelengths for relevant fluorophores [21][22][23][24][25].…”

Optical biopsy - a new armamentarium to detect disease using light

“…Contrast is important in differentiating target objects (for instance, the tumors) from background (normal tissue) [20]. The key optical methods to be presented are: fluorescence [21], Stokes Shift [22], elastic backscattering reflectance [23], Raman [24], and timeresolved spectroscopy [25] mainly based on the achievement at the Institute for Ultrafast Spectroscopy and Lasers (IUSL) at City College of New York. To understand the underlying physical and biological basis from spectral changes of these optical approaches, various mathematical algorithms analyzing methods will be described and discussed such as Principal Component Analysis (PCA) [26], Independent Component Analysis (ICA) [27], Multivariate Curve Resolution with Alternating Least-Squares (MCR-ALS) [28], and Nonnegative Matrix Factorization (NMF) [29].…”

Stokes shift spectroscopic analysis of multifluorophores for human cancer detection in breast and prostate tissues

“…8 Most recently, the S3 technique has received increasing interest for diagnostics of different types of cancers in human tissues. 8,9 The aim of this paper is to show the usefulness of the S3 technique to distinguish the malignant tissues from the normal for the human breast and prostate tissues samples. The optimal Stokes shift interval, Δλ i , for S3 measurements was investigated and determined.…”