Fiber Spectroscopy for Tumor Margin Detection

According to World Health Organization (WOH), cancer is one of leading causes of morbidity and mortality worldwide, with approximately 14 million new cases and 8.2 million cancer related deaths per year [Stewart B. et al., International Agency for Research on Cancer, 2014].

Early diagnostic and treatment of cancer are currently the recommended management strategy, which can significantly reduce the cancer mortality.

However, the current procedure for cancer diagnostic consisting of a clinical examination of the suspicious lesion, followed by biopsy and histopathology is invasive, costly, and time-consuming. Non-invasive spectroscopic investigation or “spectral histopathology” is a novel alternative for rapid cancer diagnostic and label-free cancer specification.

Thanks to art photonics’ spectroscopy fiber probe technology, cancer specialists can “see into future” and identify deadly diseases before can break out. New endoscopic fiber probes can detect inflammation in the thinnest folds of the human digestive system that are invisible to the naked eye.

art photonics’ founder and CEO Dr. V. Artyushenko said, “we developed and apply various single and combined fiber optic probes and sensors for spectroscopic measurements in broad spectral region to increase the efficiency, effectivity and success rates of cancer surgeries. Fiber optic probes allow a remote sensing for tissues annotation both in laboratory and clinical environment. As an example, thin   Raman endoscopic probes allow to bring high sensitivity measurements to the clinical surgery room. For farther increasing of detection sensitivity and efficiency, we present synergy of key spectroscopic methods in multi spectral optical fiber system consisting Fluorescence spectroscopy, NIR-diffuse reflection, Raman and Fourier transform infrared (FTIR) as a potential approach to indicate tumor cells in tissue during the surgical  operations”.

Malignant and healthy tissue can be differentiated by NIR-diffuse reflection, Raman scattering, Mid IR absorption, or fluorescence spectroscopy. All these methods were tested on kidney cancer samples to evaluate their potential for cancer detection. Eventually, they can be also combined in any configuration to enhance sensitivity, specificity, accuracy and level of predictive value for in-vivo diagnostics.

Malignant and healthy tissue can be differentiated by NIR-diffuse reflection, Raman scattering, Mid IR absorption, or fluorescence spectroscopy. All these methods were tested on kidney cancer samples to evaluate their potential for cancer detection. Eventually, they can be also combined in any configuration to enhance sensitivity, specificity, accuracy and level of predictive value for in-vivo diagnostics.

Multispectral fiber system

Fig.1 Multispectral fiber system. Image credit: Art Photonics GmbH

Multi-spectral fiber MSF-systems coupled with flexible fiber probes (Fig.1) should be used in clinical trials to select the most sensitive, specific & accurate method for malignant tissue diagnostics at research phase, leading to special spectral fiber sensors development  dedicated to detect specific tumor margins.

Miniaturized Fiber Probes

Fiber probes for MSF-systems and Tumor Margin Sensors (Fig.2) should be miniaturized to enable their integration in endoscopes and must be produced as disposable or sterilizable for clinical applications. Polycrystalline IR (PIR-) fiber ATR-probes, for example, can be used for molecular tissue analysis in-vivo as may fit into tiny needles using the mono-fiber probe design [US Patent US 7,956,317 B2].

a) TM-Sensor; b) Fluorescence probe; c) MIR-needle; d) Raman probe

Fig.2 a) TM-Sensor; b) Fluorescence probe; c) MIR-needle; d) Raman probe. Image credit: Art Photonics GmbH

Tissue Spectra in MIR Range

ATR-Absorption spectra collected to distinguish between normal and cancer kidney tissue with an ATR PIR-fiber probe are shown in Fig. 3. The main differences were observed at 1000cm-1 which is tentatively assigned to glucose. Results for in-vitro samples for kidney cancer from 10 patients was well confirmed for the 1st test of sample ex-vivo (2 hours after operation) – with substantial difference of normal & cancer tissue.

ATR-spectra of kidney & ex-vivo samples

Fig.3 ATR-spectra of kidney & ex-vivo samples. Image credit: Art Photonics GmbH

Fluorescence

Auto-fluorescence can be used to distinguish cancerous from healthy kidney tissue (Fig.4). The major endogenous fluorophores with emission in the range from 450 to 650nm are flavins (FAD), bile and porphyrins. It can be clearly seen, that the ratio of the fluorescence intensity at 625-630nm (porphyrin) decreases for malignant tissue [Vengadesan N. et al., British journal of cancer, 1998, 77].

Fluorescence spectra of kidney

Fig.4 Fluorescence spectra of kidney. Image credit: Art Photonics GmbH

Diffuse Reflection Spectroscopy

With the help of NIR-DRS the ratio of water to lipid can be measured. This proportion is considered a specific biomarker for health applications. Fig. 5 depicts that it is also valuable for the detection of cancer. Clear differences are seen for averaged spectra from healthy and cancerous tissue.

The biggest spectral differences between cancer and normal tissues were observed for  first overtones and combination vibrations of OH, NH and CH bonds [Kondepati V.R. et al., Analyt. and  Bioanalyt. Chem. 2015, 387]. This differences are corresponding to the reduced level of carbohydrates and phosphates in cancer compared to non cancer tissue.

NIR-DRS-spectra of kidney tissue

Fig.5 NIR-DRS-spectra of kidney tissue. Image credit: Art Photonics GmbH

Raman Scattering Spectroscopy

This method is complementary to MIR absorption and therefore adds further information to distinguish between different samples.  In Fig. 6 spectra from healthy and cancerous samples are overlapped after normalization of normal tissue spectra. Raman spectra from healthy samples are very weak vs to much more intensive fluorescence, while Raman for cancer can be easily detected.

Raman spectra of kidney tissue

Fig.6 Raman spectra of kidney tissue. Image credit: Art Photonics GmbH

 

Summary:

Optical fiber spectroscopy enables to develop fiber sensors for oncology – to be used for differentiation of cancer and normal tissue by in-vitro & ex-vivo methods - up to in-vivo in the future. While all spectroscopy methods can help to detect tumor margins for complete and minimal invasive cancer removal – the main challenge is to select the most sensitive, specific and accurate spectroscopy

 

This information has been sourced, reviewed and adapted from materials provided by art photonics GmbH.

For more information on this source, please visit art photonics GmbH.

Citations

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    art photonics GmbH. (2020, October 19). Fiber Spectroscopy for Tumor Margin Detection. AZoM. Retrieved on October 27, 2020 from https://www.azom.com/article.aspx?ArticleID=15295.

  • MLA

    art photonics GmbH. "Fiber Spectroscopy for Tumor Margin Detection". AZoM. 27 October 2020. <https://www.azom.com/article.aspx?ArticleID=15295>.

  • Chicago

    art photonics GmbH. "Fiber Spectroscopy for Tumor Margin Detection". AZoM. https://www.azom.com/article.aspx?ArticleID=15295. (accessed October 27, 2020).

  • Harvard

    art photonics GmbH. 2020. Fiber Spectroscopy for Tumor Margin Detection. AZoM, viewed 27 October 2020, https://www.azom.com/article.aspx?ArticleID=15295.

Ask A Question

Do you have a question you'd like to ask regarding this article?

Leave your feedback
Submit