Micro-FTIR spectroscopy as robust tool for psammoma
Micro-FTIR is a spectroscopy technique that is typically used to determine the functional structure of organic chemicals.
Specimens used in this work were obtained from a human thyroid organ surgically removed after The presence of psammoma bodies (PBs)ò.
We concentric lamellated calcified structures, in thyroid tissues is considered a reliable diagnostic marker for Papillary thyroid carcinoma (PTC).
It has been correlated to aggressive tumour behaviours such as multifocality and lymph node metastasis.
Fourier transform infrared (FTIR) microspectroscopy already proved to be a powerful tool for biological tissues study thanks to its ability to spatially resolve information.
Micro-FTIR maps were collected from thyroid tumour resections and analysed by multivariate unsupervised Principal Component Analysis (PCA) and Clustering (K-means and fuzzy c-means clustering) techniques. The resulting spectral images were compared to the corresponding hematoxylin-eosin stained tissue section which provided histopathological validation.
The 850-1100 cm-1 spectral range was the most reliable for detection of PBs and the characteristic bands of carboapatite, present in this region, were correctly identified by the multivariate techniques.
These findings disclose the possibility to use a combination of FTIR microspectroscopy and multivariate spectral processing as objective and robust tools for automated PBs recognition and consequently for PTC early diagnosis.