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Towards virtual biopsy. Multimodal spectroscopy for
cancer detection
Ivan A. Bratchenkoa, Dmitry N. Artemyeva, Oleg O. Myakinina, Julia A. Kristophorovaa, Alexander A. Moryatovb,
Sergey V. Kozlovb and Valery P. Zakharova
a - Samara National Research University b - Samara State Medical University
2.6.2017 Oulu
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MOTIVATIONS
SETUP
AF STIMULATED BY 785 NM LASER
AF STIMULATED BY 457 NM LASER
RAMAN SPECTROSCOPY
DA AND PCA ANALYSIS
IN VIVO STUDIES
CONCLUSIONS
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MOTIVATIONS
Fig. 3 – Cancer mortality-to-incidence ratio (Lancet Oncol.)
UK
USA
RUS
Fig. 2 – Causes of death (BMJ) Fig. 1 – Skin cancer mortality
melanoma
other
76%
heart disease
cancer
medical error
other
36% 34%
15%15%
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MOTIVATIONS
Fig. 4 – Skin structure
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MOTIVATIONS
Raman spectroscopy (RS) measures weak inelastic scattering of light on tissue components; diagnostic accuracy near 90% and 85% in internal organs and skin pathologies studies.
Autofluorescence (AF) is light emission from tissue components after the light absorption; diagnostic accuracy near 70 – 90%.
• RS: Amide bands, collagens, proteins, etc.
• AF VIS: flavins, porphyrins, lipids
• AF NIR: melanin
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SETUP
Fig. 5 – Experimental setup. L: lenses, M: Mirrors, BPF: band-pass filters, LPF: long-pass filters
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AF STIMULATED BY 457 NM LASER
Fluorophore Excitation, nm Emission, nm
Lipo-pigments
Protoporphyrin
Protoporphyrin
Flavins 450 535
Fig. – AF spectra of skin tissues
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AF STIMULATED BY 457 NM LASER
Fig. 7 – Skin tissues classification
Fλ457 =|λnorm-λtumor| FI457 = I610/I570
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AF STIMULATED BY 785 NM LASER
Fig. 8 – AF spectra of skin tissues Fig. – Approximation of melanoma spectrum
𝐼𝑎𝑝 λ = 𝐹𝐼785 ∗ 𝑒𝑥𝑝𝐹λ785
λ
λ𝑚𝑎𝑥 + 𝑐
FI785 is the convex or concave of the approximating curve
Fλ785 characterizes the AF spectra curvature degree
𝜆𝑚𝑎𝑥 = 870 is the right boundary of the approximation interval
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AF STIMULATED BY 785 NM LASER
Fig. – Skin tissues classification with AF NIR criteria
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RAMAN SPECTROSCOPY
Fig. 11 – Raman spectra of skin tissues
Raman scatterer Raman band, cm-1
stretching mode C = N
twisting, wagging of bending mode CH2
CH2 deformations of proteins and lipids
1440 - 1460
stretching mode C = O in amide I
1640 - 1680
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PHASE PLANE AND PCA ANALYSIS
Fig. 13 – MM vs BCC by PCA
Fig. 12 – MM vs BCC by phase plane line discriminant analysis(AF vis and AF NIR criteria)
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IN VIVO STUDIES
Fig. 13 – In vivo studies design
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IN VIVO STUDIES. PLS ANALYSIS
Fig. 14 – Normalized AF + Raman spectra and VIP scores
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SKIN TISSUES CLASSIFICATION
Method Sensitivity Specificity Accuracy
Raman 97.4% 62.2% 80.3%
NIR AF 92.3% 37.5% 64.6%
VIS AF 80% 77.8% 78.4%
VIS AF + NIR AF 70% 92.6% 86.5%
Raman + NIR AF 94.9% 92.5% 93.7%
Raman + AF 100% 96.3% 97.3%
PLS in vivo 89.5% 78.4% 82.1%
Benign vs Malignant 100% 100% 100%
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CONCLUSIONS
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•Multiparametric method demonstrates high-precision in MM and BCCseparation (>95% accuracy), thus it may be used for mass screeningapplications.
•Proposed method of spectral coefficients DA can be implemented as PLSanalysis; PLS-DA provides high accuracy for skin tumors classification evenwith low-cost equipment.
•Further enhancement of diagnostics effectiveness may be achieved byincluding of imaging modalities i.e. OCT and hyperspectral imaging.
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BioPhotonics Lab Team
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Bratchenko, Ivan A.Associate Prof. of Laser and Biotechnical Systems
Dept., Leading researcher of “Photonics” Laboratory of
Samara National Research University
443086 Russia, Samara, Lukacheva str., 39b, office 314
Email: [email protected]: + 7 (846) 267-45-50
