Detection Challenges in Clinical Diagnostics
CHAPTER 8: The Prospects for Real‐Time Raman Spectroscopy for Oesophageal Neoplasia
Published:23 Sep 2013
Special Collection: 2013 ebook collection , 2011-2015 analytical chemistry subject collectionSeries: Detection Science
Max Almond, Gavin Rhys‐Lloyd, Jo Hutchings, Geeta Shetty, Neil Shepherd, Catherine Kendall, Nicholas Stone, Hugh Barr, 2013. "The Prospects for Real‐Time Raman Spectroscopy for Oesophageal Neoplasia", Detection Challenges in Clinical Diagnostics, Pankaj Vadgama, Serban Peteu
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Raman spectroscopy can provide exquisite sensitivity for molecular analysis of degenerating pre malignant changes in the oesophagus. We are interested in the prospect of rapid endoscopic diagnosis during endoscopy using Raman. The early changes of dysplasia are invisible to white‐light inspection. If detected, the dysplastic area can then be immediately removed and the surrounding area treated. The problem has been that histopathological classification, which is very challenging in these very early abnormalities. We have built prognostic models to classify these areas of abnormality and related the spectral classification to the patient prognosis and development of invasive cancer. The hypothesis is that the Raman signature allows biochemical detection at a biochemical and molecular level prior to morphological changes within the tissue. It is becoming clear that the dependence on the histological appearance of cells to establish a diagnosis of these early changes is subject to great variation and can be highly subjective. In addition, pathological analysis of tissue is very time consuming, expensive, and requires tissue biopsy. Kerkhof et al. demonstrated a poor level of interobserver agreement between expert histopathologists (K=0.58) in the grading of low‐grade (LGD) and high‐grade (HGD) oesophageal dysplasia. This distinction has vital consequences for patient management as LGD can be monitored by serial surveillance endoscopy, whereas HGD necessitates early endoscopic therapy or even surgery, and carries a significant risk of malignant progression. As well as being difficult to classify histologically, dysplasia can be extremely difficult or even impossible to recognise at endoscopy. Raman spectroscopy (RS) could remove the subjectivity from the histopathological assessment by measuring precise biochemical information about the target tissue. A Raman fibre‐optic probe could also enable real‐time diagnosis facilitating immediate treatment of suspicious areas of tissue during endoscopy, and could be used as a surgical adjunct.