Clinical experiences with optical coherence tomography in epithelial (pre)malignancies

Abstract

This thesis describes the potential of optical coherence tomography (OCT) to differentiate between normal tissue and (pre)malignant tissue in epithelial cancers. It can be divided in research performed in the genital area and the field of melanoma. Chapter 2 describes the principles of the OCT-technique and provides an overview of the diagnostic value of OCT in different epithelial (pre)malignant lesions. Both qualitative and quantitative analyses of OCT-images of suspicious vulvar lesions are described in Chapter 3. We concluded that epidermal layer thickness and attenuation coefficient subtracted from OCT-images can differentiate between normal vulvar tissue and tissue containing vulvar intraepithelial neoplasia (VIN). VIN can proceed to vulvar squamous cell carcinoma (VSCC). During excision of VSCC it is important to keep excisional margins around the tumour wide enough to prevent recurrence, but simultaneously, preserve vulvar tissue to diminish genital mutilation. In Chapter 4 we assessed the value of OCT in determining appropriate surgical margins in patients operated for VSCC. The results suggest that OCT imaging is able to distinguish between benign and (pre)malignant vulvar tissue, enabling appropriate surgical margin detection. In men, epithelial skin changes that can proceed into penile cancer are covered by the term ‘penile intraepithelial neoplasia’ (PIN). OCT imaging could reduce the (painful) biopsies that are needed before treatment starts. In Chapter 5 patients with a suspicious lesion of the penis were imaged with OCT. Qualitative and quantitative analysis of OCT-images of suspicious penile lesions showed differences between benign lesions and (pre)malignant lesions. In Chapter 6 we studied pigmented skin lesions that are suspicious for melanoma. We studied 200 OCT-images of pigmented lesions and the results were correlated to the histopathology reports of the excised lesions. The µoct was different between benign and malignant lesions. The learning curve and inter-observer variance in quantification of the OCT attenuation coefficient were studied in Chapter 7. Three students were taught how to interpret OCT-images and calculate the µoct. We concluded that routine µoct determination for tissue classification does not require extensive training. For smaller scale clinical studies a consensus evaluation of OCT attenuation data is recommendable.