A fiber sensor has been developed that could facilitate the diagnosis of the disease and the identification of the most appropriate therapies starting from the detection of the presence of thyroglobulin in the washing liquid of the fine needle aspiration. The results are the result of a study born from the collaboration between three institutes of the National Research Council of Naples – the ‘Gaetano Salvatore’ Institute for Endocrinology and Oncology (Cnr-Ieos), the Institute of Chemical Sciences and Technologies ‘Giulio Natta’ (Cnr-Scitec) and the Institute of Applied Sciences and Intelligent Systems ‘Eduardo Caianiello’ (Cnr-Isasi) – the Department of Engineering of the University of Sannio and the Department of Clinical Medicine and Surgery of the University of Naples Federico II.
The device – described in an article published in ‘Biosensors and Bioelectronics’ – is able to identify and measure the presence of a particular protein, thyroglobulin, in the washing liquid of the fine needle aspiration. The evaluation of the presence of this protein in the lavage fluid of needle aspirations obtained from lymph nodes ‘suspected’ of metastases is currently one of the methods which allows with certainty the diagnosis of extrathyroidal extension of the tumor tissue. Therefore the outcome of this examination is particularly important both in the initial surgical approach and for the subsequent follow-up of the patients. Thyroglobulin is in fact a protein present, under normal conditions, exclusively in the thyroid. Its identification in the lymph nodes is, however, indicative of the presence of metastases.
To date – a note from the Cnr details – the localization of this protein requires the use of sophisticated dosage methods based on equipment that exploits specific antibodies, with detection times that are not immediate and not easily applicable in the operating room in case of diagnostic doubts. For this reason, it is often the surgeon who has to evaluate, based on his own experience, the extent of the operation to be performed without being able to make use of any instrumental support. The novelty obtained by the research group consists in having developed a new fiber sensor, based on the analysis of scattered light, which allows the identification, in real time and with high sensitivity, of thyroglobulin in the washing liquid of the fine needle aspiration thyroid lymph nodes.
“Enabling the sensitive and selective detection of human thyroglobulin in the aspirate needle wash fluid immediately prior to surgery, or directly in the operating room, would be of the utmost importance to optimize and personalize patient treatments with a minimally invasive procedure and without further risks”, explains Paolo Macchia of the Department of Clinical Medicine and Surgery of the Federico II of Naples.
The developed biosensor – continues the note – exploits the diffusion of laser radiation and allows the identification of thyroglobulin thanks to the analysis of the color of the light it reflects (Raman diffusion). The result is particularly important also because the protein to be identified is present in minimal quantities in the sample, together with many other molecules and substances that could mask its presence.
The biosensor can be made both on a chip and on a fiber, and therefore could also be used directly inside the needle during sample collection. If the results are validated in preclinical and clinical studies – explains the Cnr – the biosensor could be used for screening, diagnosis, selection of therapy and monitoring of the progression of thyroid cancer and any relapses. Furthermore, in the future the technique could be extended to the identification of metastases from other types of tumours. The result was made possible thanks to the support of the Ministry of University and Research (Mur), the Airc Foundation for cancer research and the Ciro and Cnos infrastructures in Campania.
