The clinical implementation of optical spectroscopy in colorectal cancer surgery

The standard treatment in patients with colorectal cancer is surgery. For locally advanced rectal cancer this is more often combined with neoadjuvant (chemo)-radiotherapy. During colorectal cancer surgery a balance should be found between complete removal of the tumor and sparing as much healthy tissue as possible to prevent complications. A technique that can provide real-time tissue classification during surgery might be of great benefit for the surgeon to prevent positive resection margins and complications due to too extensive surgery.
In this thesis fiberoptic diffuse reflectance spectroscopy (DRS) and diffuse reflection hyperspectral imaging (HSI) are examined as real-time tissue classification techniques that can ultimately be used during colorectal cancer surgery. In both techniques the interaction between tissue and light is examined. Providing information on tissue constituents and structure. Based on this information healthy tissue could potentially be discriminated from tumor tissue in colorectal cancer.
It was found in ex vivo and in vivo studies that fiberoptic DRS can be used to distinguish tumor from healthy surrounding tissue, including fat and healthy colorectal wall. However, the discrimination of tumor from fibrosis is more difficult and should be examined further. Furthermore, it was found that measurements obtained ex vivo can be used to train a classifier, which can successfully be used for in vivo tissue discrimination. For diffuse reflection HSI only ex vivo studies were performed. For this technique it was possible as well to distinguish tumor from healthy surrounding tissue. Finally, a generic classification method was found for diffuse reflectance spectroscopy measurements in colorectal cancer surgery.