Multi-centre Raman spectral mapping of oesophageal cancer tissues: a study to assess system transferability

Abstract

The potential for Raman spectroscopy to provide early and improved diagnosis on a wide range of tissue and biopsy samples in situ is well documented. The standard histopathology diagnostic methods of reviewing H&E and/or immunohistochemical (IHC) stained tissue sections provides valuable clinical information, but requires both logistics (review, analysis and interpretation by an expert) and costly processing and reagents. Vibrational spectroscopy offers a complimentary diagnostic tool providing specific and multiplexed information relating to molecular structure and composition, but is not yet used to a significant extent in a clinical setting. One of the challenges for clinical implementation is that each Raman spectrometer system will have different characteristics and therefore spectra are not readily compatible between systems. This is essential for clinical implementation where classification models are used to compare measured biochemical or tissue spectra against a library training dataset. In this study, we demonstrate the development and validation of a classification model to discriminate between adenocarcinoma (AC) and non-cancerous intraepithelial metaplasia (IM) oesophageal tissue samples, measured on three different Raman instruments across three different locations. Spectra were corrected using system transfer spectral correction algorithms including wavenumber shift (offset) correction, instrument response correction and baseline removal. The results from this study indicate that the combined correction methods do minimize the instrument and sample quality variations within and between the instrument sites. However, more tissue samples of varying pathology states and greater tissue area coverage (per sample) are needed to properly assess the ability of Raman spectroscopy and system transferability algorithms over multiple instrument sites.

Clinical applications of infrared and Raman spectroscopy: state of play and future challenges

“…The patient perspective is of course of critical importance [195] It is also important that the robustness of the techniques is evaluated, in terms of reproducibility of the diagnostic performance of individual instruments and comparison of different instruments, and operators, sites, etc.. In recent years, a limited amount of attention has been paid to such considerations, and notably, Isabelle et al conducted a UK based multi-centre trial of Raman spectral mapping of oesophageal cancer tissues [196]. They developed a classification model to discriminate between adenocarcinoma (AC) and non-cancerous intraepithelial metaplasia (IM) oesophageal tissue samples, measured on three different Raman instruments in three different locations.…”

Mirrored stainless steel substrate provides improved signal for Raman spectroscopy of tissue and cells

“…Furthermore, as part of ongoing studies into the routine application RS in clinical diagnosis we are currently building discriminatory models for both colorectal and esophageal cancers on stainless steel substrate. These proof of principle models, along with our recent advances in minimizing inter‐instrument system variability, underpin a thorough assessment of the clinical potential of this very promising material.…”

Discrimination of malignant and normal kidney tissue with short wave infrared dispersive Raman spectroscopy

“…RS has been used for the evaluation of bladder, prostate and kidney tumors . It provides several benefits to the clinician.…”