Different optical properties between human hepatocellular carcinoma tissues and non-tumorous hepatic tissues In Vitro

Abstract

There has been an ongoing search for clinically acceptable methods for the accurate, efficient and simple diagnosis and prognosis of hepatocellular carcinoma (HCC). Optical spectroscopy is a technique with potential clinical applications to diagnose cancer diseases. The purpose of this study was to obtain the optical properties of HCC tissues and non-tumorous hepatic tissues and identify the difference between them. A total of 55 tissue samples (HCC tissue, n=38; non-tumorous hepatic tissue, n=17) were surgically resected from patients with HCC. The optical parameters were measured in 10-nm steps using single-integrating-sphere system in the wavelength range of 400 to 1800 nm. It was found that the optical properties and their differences varied with the wavelength for the HCC tissue and the non-tumorous hepatic tissue in the entire wavelength range of research. The absorption coefficient of the HCC tissue (1.48±0.99, 1.46±0.88, 0.86±0.61, 2.15±0.53, 0.54±0.10, 0.79±0.15 mm(-1)) was significantly lower than that of the non-tumorous hepatic tissue (2.79±1.73, 3.13±1.47, 3.06±2.79, 2.57±0.55, 0.62±0.10, 0.93±0.16 mm(-1)) at wavelengths of 400, 410, 450, 1450, 1660 and 1800 nm, respectively (P<0.05). The reduced scattering coefficient of HCC tissue (5.28±1.70, 4.91±1.54, 1.26±0.35 mm(-1)) and non-tumorous hepatic tissue (8.14±3.70, 9.27±3.08, 2.55±0.57 mm(-1)) was significantly different at 460, 500 and 1800 nm respectively (P<0.05). These results show different pathologic liver tissues have different optical properties. It provides a better understanding of the relationship between optical parameters and physiological characteristics in human liver tissues. And it would be very useful for developing a non-invasive, real-time, simple and efficient way for medical management of HCC in the future.

Diffuse reflectance spectroscopy of human liver tumor specimens - towards a tissue differentiating optical biopsy needle using light emitting diodes

“…3 suggest that the optical properties of tissue types contain the most discriminative information for tissue classification in the VIS wavelength range between 450 nm and 750 nm. These findings are similar to those that have been reported for different ex vivo studies on human liver tissue of tumor patients with primary cancer [14], as well as with liver metastases [17][18][19].…”

“…Extracted from diffuse reflectance spectra, Nachabé et al [18] have shown that the amount of bile in metastatic tumor tissues is 80% lower than in healthy liver tissue. Although, primary liver cancer cells can produce bile, the diffuse reflectance spectra show comparable results of absorption in the wavelength range between 400 nm and 500 nm with spectra of metastases [14]. Yu et al explain this finding with the presence of an additional chromophore existing mainly in the liver parenchyma called cytochrome P-450 [14].…”

“…Although, primary liver cancer cells can produce bile, the diffuse reflectance spectra show comparable results of absorption in the wavelength range between 400 nm and 500 nm with spectra of metastases [14]. Yu et al explain this finding with the presence of an additional chromophore existing mainly in the liver parenchyma called cytochrome P-450 [14]. This chromophore has its main absorption peak at 450 nm and its presence is relatively lower in primary liver cancer [32].…”

“…Spectroscopic detection of malignant tumors in liver specimens has been successfully performed for primary liver cancer [14] and liver metastases in humans [15][16][17][18][19] as well as in animal models [20,21]. In a clinical ex vivo study by Evers et al [17] liver specimen of 24 patients who underwent surgery for colorectal liver metastases were analyzed with DRS in the visible (VIS) and near infrared (NIR) spectral range.…”

“…Total hemoglobin, fat and bile content turned out to be most discriminative parameters for tissue differentiation. Yu et al [14] obtained optical properties from 38 ex vivo human liver tissues with HCC. Using the VIS wavelength range, absorption and scattering coefficients were significantly different between non-and tumorous tissue mainly between 400 nm and 500 nm.…”