Cancerous Tissue Diagnosis by LIF Spectroscopy Derived From Body-Compatible Fluorophores

Abstract

Introduction: The laser-induced fluorescence (LIF) method as molecular emission spectroscopy is used to diagnose cancerous tissues. According to the previous reports, the red-shift in the fluorescence spectrum from Rhodamine 6G (Rd6G)-stained cancerous tissues compared to healthy ones impregnated with the same dye provides the feasibility for diagnosis. In this paper, we have employed the LIF emissions as a diagnostic method to distinguish between cancerous and healthy tissues infiltrated by a body-compatible fluorophore to avoid the toxicity and hazard of Rd6G dye. Methods: Biological tissue specimens are stained with sodium fluorescein (NaFl) dye and then irradiated by the blue CW diode laser (405 nm) to examine the spectral properties that are effective in detecting cancerous tissues. Results: The spectral shift and the intensity difference of fluorescence are keys to diagnosing in vitro cancerous breast, colon, and thyroid tissues for clinical applications. The notable tubular densities in the breast and colon tissues and the space between the papillae in the thyroid ones cause the cancerous tissues to be prominently heterogeneous, providing numerous micro-cavities and thus more room for dye molecules. Conclusion: Here, we have assessed the spectral shift and intensity difference of fluorescence as a diagnostic method to distinguish between cancerous and healthy tissues for clinical applications.

Point‐of‐care devices based on fluorescence imaging and spectroscopy for tumor margin detection during breast cancer surgery: Towards breast conservation treatment

“…Red dotted line in the tissue microenvironment represents the random walk of incident photon within cancerous and normal tissue. [31][32][33][43][44][45] Detailed discussion of these possibilities can be elaborated as: Microenvironment of breast cancer tissue is heterogeneous in nature and more vascular compared to healthy tissues. 46 When FSS tags with the micro-partitioning structure of cancerous tissue, then deformation of the cellular composition retards the self-aggregation of dye and reduce self-quenching of FSS.…”

“…46 When FSS tags with the micro-partitioning structure of cancerous tissue, then deformation of the cellular composition retards the self-aggregation of dye and reduce self-quenching of FSS. 45 Fluorophores of FSS captured by these micro-structured environment and distance between them is increased which is responsible for reduced aggregation and suppression of fluorescence due to fluorophores. This phenomenon leads high fluorescence intensity in breast cancer tissues in comparison to healthy tissues and can be seen in Figure 5C.…”

“…This scattering and reabsorption offer the shifted emission in fluorescence spectra. [31][32][33][43][44][45] Moreover, breast tumor also acts as a diffusive and turbid medium for incident photon. 21,48 Absorption, scattering coefficient within tissue can be stated with the help of Beer-Lambert law in turbid media.…”

“…Also there is a large Forster constant (Kt) leading to a significant amount of peak shift in cancerous area compared with healthy tissues. 45…”

“…Optical path length or random walk of the incident photon is also escalated in cancerous tissue. Red dotted line in the tissue microenvironment represents the random walk of incident photon within cancerous and normal tissue 31–33,43–45 …”