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Background: Development of a nonendoscopic test for Barrett's esophagus would revolutionize population screening and surveillance for patients with Barrett's esophagus. Swallowed cell collection devices have recently been developed to obtain cytology brushings from the esophagus: automated detection of neoplasia in such samples would enable large-scale screening and surveillance.Methods: Fourier transform infrared (FTIR) spectroscopy was used to develop an automated tool for detection of Barrett's esophagus and Barrett's neoplasia in esophageal cell samples. Cytology brushings were collected at endoscopy, cytospun onto slides and FTIR images were measured. An automated cell recognition program was developed to identify individual cells on the slide.Results: Cytology review and contemporaneous histology was used to inform a training dataset containing 141 cells from 17 patients. A classification model was constructed by principal component analysis fed linear discriminant analysis, then tested by leave-one-sample-out cross validation. With application of this training model to whole slide samples, a threshold voting system was used to classify samples according to their constituent cells. Across the entire dataset of 115 FTIR maps from 66 patients, whole samples were classified with sensitivity and specificity respectively as follows: normal squamous cells 79.0% and 81.1%, nondysplastic Barrett's esophagus cells 31.3% and 100%, and neoplastic Barrett's esophagus cells 83.3% and 62.7%.Conclusions: Analysis of esophageal cell samples can be performed with FTIR spectroscopy with reasonable sensitivity for Barrett's neoplasia, but with poor specificity with the current technique. [ABSTRACT FROM AUTHOR]

We report results from a study utilizing infrared spectral cytopathology (SCP) to detect abnormalities in exfoliated esophageal cells. SCP has been developed over the past decade as an ancillary tool to classical cytopathology. In SCP, the biochemical composition of individual cells is probed by collecting infrared absorption spectra from each individual, unstained cell, and correlating the observed spectral patterns, and the variations therein, against classical diagnostic methods to obtain an objective, machine-based classification of cells. In the past, SCP has been applied to the analysis and classification of cells exfoliated from the cervix and the oral cavity. In these studies, it was established that SCP can distinguish normal and abnormal cell types. Furthermore, SCP can differentiate between truly normal cells, and cells with normal morphology from the vicinity of abnormalities. Thus, SCP may be a valuable tool for the screening of early stages of dysplasia and pre-cancer. [ABSTRACT FROM AUTHOR]

Abstract: Fourier transform infrared spectroscopic (FTIR) interrogation of biological tissues in real time has largely been a challenging proposition because of the strong absorption of mid-infrared light in water filled tissues. To enable sampling of tissues they must be sectioned and dried, which has time and resource implications. FTIR of touch imprint cytology (TIC) has been proposed to circumvent this problem. TIC is a well known histopathological method of rapidly analysing biological tissues. In this article we demonstrate the ability of FTIR of TIC to provide detailed spectra which can be used to differentiate various tissue pathologies. FTIR spectral profiles of TIC of lymph node and thyroid tissues differ visually when compared with TIC spectra of parathyroid tissue. The lymph node showed strong lipid spectral peaks at 1166cm−1 and 1380cm−1 including a very strong carbonyl-ester band at 1748cm−1, and a strong methylene bending band (scissoring, at 1464cm−1). Smaller intensity protein peaks at 1547cm−1 and 1659cm−1 were also seen. The thyroid spectra, in addition to evident strong protein peaks at 1547cm−1 and 1659cm−1, also demonstrated possible nucleic acid signals at 1079cm−1 and 1244cm−1. The C-OH peak at 1037cm−1 was attributed to carbohydrate signals. Parathyroid adenoma showed a marginal shift to lower wavenumbers with decreased amide I and II peak intensities when compared to hyperplasia. Nucleic acid peak positions at 1079cm−1 and 1244cm−1 were of higher intensity in adenomas compared to hyperplastic glands possibly demonstrating an increase in cell proliferation and growth. This study demonstrates the feasibility of cytoimprint FTIR for the intraoperative diagnosis of tissue during surgical neck exploration for the management of hyperparathyroidism. There is potential for the application of the technique in sentinel lymph node biopsy diagnosis and tumour margin evaluation. [Copyright &y& Elsevier]

Summary: 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. [Copyright &y& Elsevier]