B143
Novel Raman probe for optical biopsy at endoscopy
Catherine Kendall1, John Day2, Joanne Hutchings1, Hugh Barr1, Nick Stone1
1Gloucestershire Hospitals NHS Foundation Trust, Gloucester, UK, 2University of Bristol, UK
Background
Detection of early cancerous changes is of vital importance. Oesophageal cancer develops through a pre-malignant condition, Barretts oesophagus [1], which is linked to an increased risk of developing adenocarcinoma. Many patients are enrolled on endoscopic surveillance programmes during which excisional biopsy samples are collected. Raman spectroscopy offers a number of potential advantages for in vivo assessment of tissue at endoscopy. Raman spectroscopy can identify and classify the subtle pre-malignant biochemical changes related to the carcinogenesis process [2]. A number of technical problems must be solved to enable routine use of Raman as an in vivo clinical tool; a novel probe design has been evaluated in this study.
Method
Ethical approval for this study enabled biopsy samples to be collected at endoscopy. 7 m frozen sections were cut, stained with haematoxylin and eosin and reviewed by three expert pathologists. Raman spectra were measured using a custom built single output fibre probe with a Renishaw Raman System 100 spectrometer using 50 mW of 830nm excitation light.
Results
1213 Raman spectra have been measured from 116 samples collected from 46 patients. Spectra acquired with a 10s acquisition period were used to train principal component fed linear discriminant classification models. The performance of which was independently tested with the projection of the 2 s spectra on to the classification models.
Conclusion
This potential of operating in the clinically practical timeframe of 1-2 seconds per spectrum was demonstrated. This would facilitate improved targeting of biopsy samples and minimise the number of normal samples collected and ultimately enable in vivo optical biopsy to be realised.
Acknowledgements
Royal Society & National Institute of Health Research
References
[1] J. Jankowski, R.F. Harrison, I. Perry, Lancet 356 (2000), 2079-2086.
[2] C. Kendall, N. Stone, N. Shepherd, K. et. al. J. Pathol. 200 (2003), 602609.
