Role of Fourier transform infrared spectroscopy (FTIR) in the diagnosis of parathyroid pathology

Background: With the advent of minimally invasive parathyroid surgery (MIPS) accurate pathological diagnosis to differentiate parathyroid adenomas from hyperplasia has become difficult for the pathologist. This is because now single glands are excised, guided by better preoperative localisation scans, while for an accurate pathological diagnosis, at least a two-gland biopsy is required. Ultimately, an accurate pathological diagnosis to establish the aetiology is essential for the management of hyperparathyroidism. To resolve this issue we evaluated the ability of FTIR to accurately differentiate between parathyroid adenoma and hyperplasia using their biochemical signatures. Methods: Samples of diseased glands were collected intraoperatively from consenting patients over a 1-year period. Sixteen glands were analysed - eight hyperplasias and eight adenomas. Samples were analysed using an infrared spectroscope and reflected the biochemical nature of the sample tissue. Spectra collected were subjected to both empirical and multivariate analytical techniques. Results: Empirical analysis highlighted differences in spectral protein peaks, with possibly additional subtle differences in nucleic acid spectra between the pathologies. A multivariate statistical predictive model demonstrated the sensitivity of FTIR for adenomas to be 93% and hyperplasia 93%, (88% on cross validation testing). Conclusions: Thus, infrared spectroscopy is potentially an excellent tool to differentiate the two pathologies and could be a useful adjunct to the pathological diagnosis of single glands. (C) 2007 Elsevier B.V. All rights reserved.