Raman spectroscopy with a 1064-nm wavelength laser as a potential molecular tool for prostate cancer diagnosis: a pilot study

Abstract

Raman spectroscopy is widely used to investigate the structure and property of the molecules from their vibrational transitions and may allow for the diagnosis of cancer in a fast, objective, and nondestructive manner. This experimental study aims to propose the use of the 1064-nm wavelength laser in a Raman spectroscopy and to evaluate its discrimination capability in prostate cancer diagnosis. Seventy-four spectra from patients who underwent radical prostatectomy were evaluated. The acquired signals were filtered, normalized, and corrected for possible oscillations in the laser intensity and fluorescence effects. Wilcoxon tests revealed significant differences between the benign and malign samples associated with the deformation vibration characteristic of nucleic acids, proteins, and lipids. A classifier based on support vector machines was able to predict the Gleason scores of the samples with 95% of accuracy, opening a perspective for the use of the 1064-nm excitatory wavelength in prostatic cancer diagnosis.

Chemometrics-Enabled Raman Spectrometric Qualitative Determination and Assessment of Biochemical Alterations during Early Prostate Cancer Proliferation in Model Tissue

“…e spectra demonstrate a similar spectral pattern although there are minor Raman shifts. e figure reveals the mean positions (and the standard errors) of major Raman band contributions for the two cell lines, whose biochemical assignments are well explained in literature [9,13,16,29,30].…”

“…Generally, the difference spectra show PC3 cells, exhibiting prominent biochemical alterations at 566 ± 0.70 cm − 1 (cytosine and guanine), 630 cm − 1 (glycerol), 972 ± 1.17 cm − 1 (cytosine and proteins), 1186 cm − 1 (guanine, cytosine, adenine, and antisymmetric phosphate vibrations), 1520 ± 1.41 cm − 1 (cytosine, C-C stretch, and C�C stretch mode (β-carotene accumulation)), and 1743 cm − 1 (ester groups) [9,16,[29][30][31]. Similarly, PNT1a samples have prominent biochemical alterations at 550 ± 0.23 cm − 1 (cytosine, guanine, tryptophan, and glycerol), 719 ± 1.31 cm − 1 (phospholipids and nucleic acids), 852 ± 0.47 cm − 1 (proline, tyrosine, and polysaccharides), 948 ± 1.88 cm − 1 (valine and proline), 1250 ± 2.86 cm − 1 (amide III, lipids, adenine, and cytosine), 1332 ± 1.64 cm − 1 (nucleic acids and CH 3 CH 2 wagging of collagen), 1450 ± 2.20 cm − 1 (lipids and proteins), and 1660 cm − 1 (amide I and lipids) [13,30,31]. If we consider stage 2 and 3 spectral datasets, it is observed PNT1a cells spectra have prominent band alterations at 623 cm − 1 (phenylalanine and adenine), 664 cm − 1 (guanine, thymine, and collagen), 898 ± 0.20 cm − 1 (proline and saccharides), 1066 cm − 1 (proline of collagen), 1152 ± 1.44 cm − 1 (proteins and carotenoids), 1370 ± 0.86 cm − 1 (saccharides), 1573 cm − 1 (guanine, adenine, and tryptophan proteins), 1618 ± 1.73 cm − 1 (tryptophan), and 1675 cm − 1 (amide I (β-sheet)) [30,31].…”

“…In this study, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) bands in the 1000-1400 cm − 1 region were observed to be the most significant for segregation between the prostate tissues archived over a period of three decades. In [13], the applicability of 1064 nm wavelength in prostate cancer diagnosis was evaluated where spectral markers associated with proteins, lipids, and nucleic acids differentiated malignant and benign samples, mainly in the 1000-1450 cm − 1 region. A support vector machine (SVM) classification model predicted Gleason scores of samples with an overall accuracy of 95%.…”

Using the Method of “Optical Biopsy” of Prostatic Tissue to Diagnose Prostate Cancer

“…Since tumor development is accompanied by structural and biochemical modifications of the tissue, by registering these changes, Raman spectroscopy makes possible identification of various morphological forms of PC, as well as concurrent hyperplastic or preneoplastic processes. Numerous studies have proven this method of examining the prostatic tissue [ 10 , 11 , 12 , 13 , 14 ] and blood plasma [ 15 ] potentially viable in diagnosing prostate cancer.…”

“…In other scientific works [ 11 , 12 , 13 , 14 ], the possibilities of Raman spectroscopy with excitation at different wavelengths of laser radiation (633, 785, and 1064 nm) were investigated. In this works, the differences in the average spectra of cancer and control groups were analyzed, or the method of principal components was applied.…”