Thyroid tissue analysis through Raman spectroscopy

Abstract

The diagnosis of thyroid pathologies is usually made by cytologic analysis of the fine needle aspiration (FNA) material. However, this procedure has a low sensitivity at times, presenting a variation of 2-37%. The application of optical spectroscopy in the characterization of alterations could result in the development of a minimally invasive and non-destructive method for the diagnosis of thyroid diseases. Thus, the objective of this work was to study the biochemical alterations of tissues and hormones (T3 and T4) of the thyroid gland by means of molecular vibrations probed by FT-Raman spectroscopy. Through the discriminative linear analysis of the Raman spectra of the tissue, it was possible to establish (in percentages) the correct classification index among the groups: goitre adjacent tissue, goitre nodular region, follicular adenoma, follicular carcinoma and papillary carcinoma. As a result of the comparison between the groups goitre adjacent tissue versus goitre nodular region, an index of 58.3% of correct classification was obtained; this percentage was considered low, and it was not possible to distinguish the Raman spectra of these groups. Between goitre (nodular region and adjacent tissue) versus papillary carcinoma, the index of correct classification was 64.9%, which was considered good. A relevant result was obtained in the analysis of the benign tissues (goitre and follicular adenoma) versus malignant tissues (papillary and follicular carcinomas), for which the index was 72.5% and considered good. It was also possible, by means of visual observation, to find similar vibrational modes in the hormones and pathologic tissues. In conclusion, some biochemical alterations, represented by the FT-Raman spectra, were identified that could possibly be used to classify histologic groups of the thyroid. However, more studies are necessary due to the difficulty in setting a standard for pathologic groups.

In situ cellular level Raman spectroscopy of the thyroid

“…Raman spectroscopy has been applied to examine normal and cancerous thyroid tissues ex vivo and thyroid cell lines in vitro [10,11,13,14 [11]. The Raman peaks employed in this in situ cellular level thyroid study (Table 1) are overall in agreement with the peaks observed in earlier ex vivo and in vitro studies.…”

“…The Raman peaks employed in this in situ cellular level thyroid study (Table 1) are overall in agreement with the peaks observed in earlier ex vivo and in vitro studies. It is important to note that in general, thyroid tissue is very complex as there are a large number of functional groups vibrating at the same time [10,11]. Therefore, there is significant value in performing Raman spectroscopic analysis on specific cellular level structures within the thyroid.…”

“…Raman spectroscopy has been employed to study the thyroid at the bulk tissue level [10] and at the cellular level in vitro [11]. In this study, we develop a novel Raman spectroscopy method for in situ cellular level analysis of the thyroid.…”

FT-Raman spectroscopy for the differentiation between cutaneous melanoma and pigmented nevus

“…In this research, an optic biopsy technique for the study of oncological lesions was used, FT-Raman spectroscopy, a method which supplies information on the molecular structure of the sample under examination [3][4][5] . This technique has specific characteristics, appropriate for the study of the skin, both in vivo and in vitro.…”

Optical Diagnosis for Thyroid and Parathyroid Tissues—A Review

“…This article focuses primarily on the use of fluorescence spectroscopy (4-6), time-resolved fluorescence (7,8), near-infrared spectroscopy (9-11), Raman spectroscopy (12,13), infrared spectroscopy (14)(15)(16)(17), elastic scattering spectroscopy (18,19), second-harmonic generation (SHG) microscopy (20,21), and optical coherence tomography (22)(23)(24) to evaluate thyroid and parathyroid tissues.…”