Vibrational Spectroscopy and Cancer - Vibrational Spectroscopy for Tissue Analysis - page 70

technique and chemical factor analysis has the potential to be a clinical
diagnostic tool [84].
W. T. Cheng et al. reported on micro-Raman spectroscopy used to identify
and grade human skin pilomatrixoma (PMX). The normal skin dermis, collagen
type I, hydroxyapatite (HA) were used as a control. The Raman spectrum of
normal skin dermis was found to be similar to that of collagen type I, confirm-
ing that the collagen was a predominant component in normal skin dermis.
The most significant differences of the collected spectra of normal skin dermis
and soft and hard PMX were the peaks at 1665 cm −1 , which assigned to the
amide I band, and 1246 cm −1 , which assigned to the amide III band. The consid-
erable changes in collagen content and its structural conformation, the higher
content of tryptophan, and disulfide formation in PMX masses were markedly
evident. In addition, the peak at 960 cm −1 assigned to the stretching vibration
of PO 4 3− HA also appeared respectively in the Raman spectra of hard and soft
PMX masses, suggesting the occurrence of calcification of HA in the PMX tis-
sue. The results indicated that the micro-Raman spectroscopy may provide a
highly sensitive and specific method for identifying normal skin dermis and
how it differs in chemical composition from different PMX tissues [85].
S. Kaminaka et al. reported on NIR multichannel Raman spectroscopy
toward real-time in vivo cancer diagnosis. The method used enabled them
to measure an in vivo Raman spectrum of live human tissue (skin) in one
minute using fibre probe optics. By applying the system to human lung tis-
sue, they found that Raman spectroscopy makes a clear distinction not only
between normal and cancerous tissues, but also between two different parts
of lung carcinoma. The results indicated a promising future for the noninva-
sive real-time Raman diagnosis of cancer [86].
The research of S. Sigurdsson et al. was about detection of skin cancer by
classification of Raman spectra. The classification framework was probabilis-
tic and highly automated. Correct classification of 80.5% ± 5.3% for malignant
melanoma and 95.8%±2.7% for basal cell carcinoma was reported, which
are excellent and similar to that of trained dermatologists. The results were
shown to be reproducible and small distinctive bands in the spectrum, cor-
responding to specific lipids and proteins, were also shown to hold discrimi-
nating information which they used to diagnose skin lesion [87].
Diagnosis of the most common skin cancer, basal cell carcinoma (BCC),
by Raman spectroscopy was carried out by M. Gniadecka et al. Biopsies
of histopathologically verified BCC and normal skin were harvested and
analysed by NIR-FT Raman spectroscopy using a 1064 nm Nd:YAG laser
as a radiation source. The results indicated alterations in protein and lipid
structures in skin cancer samples. Spectral changes were observed in pro-
tein bands, amide I (1640-1680 cm −1 ), amide III (1220-1300 cm −1 ), and ν(C- C)
stretching (probably in amino acids proline and valine, 928-940 cm −1 ), and
in bands characteristic of lipids, CH 2 scissoring vibration (1420-1450 cm −1 ),
and −(CH 2 ) n − in-phase twist vibration around 1300 cm −1 . Moreover, possible
changes in polysaccharide structure were found in the region 840-860 cm −1 .