Polarized fluorescence study in human cervical tissue: change in autofluorescence through different excitation wavelengths

Abstract

This study aims towards applying the intrinsic fluorescence technique, extracted from polarized fluorescence, to detect subtle biochemical changes occurring during the progression of cancer from human cervical tissue samples. The efficacy of this technique, earlier validated through tissue phantoms, is tested in human cervical tissues by comparing the biochemical changes for diagnostic purpose at different wavelengths. It is pertinent to note that the co and crosspolarized fluorescence do not display the high sensitivity obtained through extracted intrinsic fluorescence. We observed that sensitivity and specificity of intrinsic fluorescence technique is high at 325 and 370nm for Collagen and NADH respectively in comparison to 350nm excitation wavelength. It may be concluded that decoupled information at 325 and 370nm wavelengths for collagen and NADH respectively, through intrinsic fluorescence provides better diagnostic parameter for early detection of cervical dysplasia. This information can provide a guiding path for designing a probe for clinical purpose.

Detecting cervical cancer progression through extracted intrinsic fluorescence and principal component analysis

“…55 Elastic scattering ðI VV − G × I VH Þ scat at the excitation wavelength is denoted by R. On an average, fluorescence and elastic scattering contribute equally to the entire path traversed by the excitation photon inside the tissue. 24,29 The factor x ¼ 0.5 takes into account this contribution. The validation of this technique has been previously reported on tissue mimicking phantoms.…”

“…We make use of a novel approach, developed earlier by our group, in effectively combining the measured polarized fluorescence with the polarized elastic scattering to remove the effects of absorption and diffuse scattering. 28,29 The main advantage of this correction technique is the recovery of both line shape and intensity information in a turbid medium with reasonable accuracy for the range of optical transport parameters, 28 where the ratio of μ a ∕μ 0 s lies between 0 and 1.8.…”