SP7.1.6 Using Diffuse Reflectance Spectroscopy (DRS) to Identify Tumour and Non-tumour Tissue in Upper Gastrointestinal Specimens

Aim Cancers of the upper gastrointestinal (GI) tract remain a major contributor to the global cancer risk. Surgery aims to completely resect tumour with clear margins, whilst preserving as much surrounding tissue. Diffuse reflectance spectroscopy (DRS) is a novel technique that presents a promising advancement in cancer diagnosis. We have developed a novel DRS system with tracking capability. Our aim is to classify tumour and non-tumour GI tissue in real-time using this device to aid intra-operative analysis of resection margins. Method An ex-vivo study was undertaken in which data was collected from consecutive patients undergoing upper GI cancer resection surgery between August 2020- January 2021. A hand-held DRS probe and tracking system was used on normal and cancerous tissue to obtain spectral information. After acquisition of all spectra, a classification system using histopathology results was created. A user interface was developed using Python 3.6 and Qt5. A support vector machine was used to classify the results. Results The data included 4974 normal spectra and 2108 tumour spectra. The overall accuracy of the DRS probe in differentiating normal versus tumour tissue was 88.08% for the stomach (sensitivity 84.8%, specificity 89.3%), and 91.42% for the oesophagus (sensitivity 76.3%, specificity 98.9%). Conclusion We have developed a successful DRS system with tracking capability, able to process thousands of spectra in a small timeframe, which can be used in real-time to distinguish tumour and non-tumour tissue. This can be used for intra-operative decision-making during upper GI cancer surgery to help select the best resection plane.