Combining scanning haptic microscopy and fibre optic Raman spectroscopy for tissue characterization

Abstract

The tactile resonance method (TRM) and Raman spectroscopy (RS) are promising for tissue characterization in vivo. Our goal is to combine these techniques into one instrument, to use TRM for swift scanning, and RS for increasing the diagnostic power. The aim of this study was to determine the classification accuracy, using support vector machines, for measurements on porcine tissue and also produce preliminary data on human prostate tissue. This was done by developing a new experimental set-up combining micro-scale TRM—scanning haptic microscopy (SHM)—for assessing stiffness on a micro-scale, with fibre optic RS measurements for assessing biochemical content. We compared the accuracy using SHM alone versus SHM combined with RS, for different degrees of tissue homogeneity. The cross-validation classification accuracy for healthy porcine tissue types using SHM alone was 65–81%, and when RS was added it increased to 81–87%. The accuracy for healthy and cancerous human tissue was 67–70% when only SHM was used, and increased to 72–77% for the combined measurements. This shows that the potential for swift and accurate classification of healthy and cancerous prostate tissue is high. This is promising for developing a tool for probing the surgical margins during prostate cancer surgery.

Keywords::

• Tactile resonance method
• Raman spectroscopy
• Prostate cancer
• Support vector machines
• Tissue characterization

Acknowledgements

This work was supported by grants from the Objective 2 Norra Norrland-EU Structural Fund and the Kempe Foundation. We wish to thank Mats Gustavsson for helping us obtaining porcine prostate samples, Kerstin Löfquist and Kerstin Stenberg at the Department of Pathology and Cytology at Sunderby Hospital for preparing porcine histology specimens, and Kerstin Almroth, Pernilla Andersson and Birgitta Ekblom at the urology and pathology units at Norrland’s University Hospital for preparing human histology specimens.

Declaration of interest:The authors report no conflicts of interest.