Spectroscopic Analysis of Parathyroid and Thyroid Tissues by Ground-State diffuse Reflectance and Laser Induced Luminescence: a Preliminary Report

Abstract

Intraoperative discrimination of thyroid and parathyroid tissues is fundamental in thyroid surgery. Recent uorescence studies have shown stronger NIR emission in parathyroid tissue than in thyroid tissue, presenting a potential avenue for the development of a tool for surgical assistance. However, the uorophore responsible for this emission has not yet been identi ed. In this work, spectroscopic analysis was performed to ascertain the origin of the emission peaks in parathyroid tissue. Ground-state diffuse re ectance (GSDR) absorption spectroscopy and laser-induced luminescence (LIL) emission spectroscopy were performed in parathyroid, thyroid, and fatty tissue samples and the resulting spectra were compared with the peaks of known uorophores to identify the origin of each peak. The spectra of the different tissue types were also compared in order to evaluate the wavelength which presents the highest parathyroid emission relative to the emission of the surrounding tissues, representing the ideal wavelength for parathyroid detection. An emission peak in these conditions was observed for both thyroid and parathyroid tissue at 711 nm, with a higher intensity in parathyroid sample, making it suitable for detection applications. These results show a potential avenue for the development of a system allowing parathyroid detection in a surgical setting.

The magic mirror: a novel intraoperative monitoring method for parathyroid glands

“…Based on these studies, we conclude that NIRAF has a satisfactory parathyroid identification rate, which makes it a reliable auxiliary equipment ( 110 ). In thyroid surgery, NIRAF is also significantly effective in reducing transient hypocalcemia after surgery.…”

Feasibility of parathyroid gland autofluorescence imaging after indocyanine green fluorescence angiography

“…This autofluorescence allowed for the pre-localization of the PTGs during thyroidectomy. More recently, Serra et al (10), using fluorescence spectrometry and excitation at 650 nm, confirmed that the PTGs emitted autofluorescence at least at 700 nm and that maximum autofluorescence was observed close to 711 nm. In order to avoid using two excitation wavelengths, we examined a single excitation that rebalanced the measured signal levels between ICG and PTG autofluorescence.…”

“…Next, a comparison of the emission spectra of PTG autofluorescence for excitation at 650 nm, as provided by Serra (10), with that of ICG (Figure 1) showed that their peak maxima were well separated. We assumed that the autofluorescence spectra for wavelengths longer than 700 nm were similar, with excitation wavelengths of 650 and 685 nm.…”

“…However, the maximum emission peaks were adequately separated. The data for the PTG spectrum was derived from the study by Serra et al (10), while that for the ICG was measured on a Perkin Elmer LS50B system. ICG (25 mg) was solubilized in sterile water (10 mL).…”

Intraoperative identification of parathyroid glands during endocrine surgery

“…Благодаря недавним исследованиям, связанным с применением индоцианина зеленого (ICG), было установлено, что перфузия ОЩЖ выше чем у ЩЖ [22]. Также существенным является тот факт, что по данным ультразвукового исследования в режиме доплеровского картирования было установлено наличие более интенсивного кровотока в ОЩЖ, чем в лимфатических узлах [23]. В силу того, что кровоснабжение ОЩЖ интенсивнее, чем у окружающих тканей, можно сделать вывод о более высокой температуре данной структуры и, как следствие, о возможности визуализации методом термографии.…”