[Show abstract][Hide abstract] ABSTRACT: Early detection of cancer remains the best way to ensure patient survival and quality of life. Squamous cell carcinoma is usually preceded by dysplasia presenting as white, red, or mixed red and white epithelial lesions on the oral mucosa (leukoplakia, erythroplakia). Dysplastic lesions in the form of erythroplakia can carry a risk for malignant conversion of 90%. A noninvasive diagnostic modality would enable monitoring of these lesions at regular intervals and detection of treatment needs at a very early, relatively harmless stage. The specific aim of this work was to test a multimodality approach [three-dimensional optical coherence tomography (OCT) and polarimetry] to noninvasive diagnosis of oral premalignancy and malignancy using the hamster cheek pouch model (nine hamsters). The results were compared to tissue histopathology. During carcinogenesis, epithelial down grow, eventual loss of basement membrane integrity, and subepithelial invasion were clearly visible with OCT. Polarimetry techniques identified a four to five times increased retardance in sites with squamous cell carcinoma, and two to three times greater retardance in dysplastic sites than in normal tissues. These techniques were particularly useful for mapping areas of field cancerization with multiple lesions, as well as lesion margins.
Journal of Biomedical Optics 07/2011; 16(7):076007. · 2.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The Mueller matrix describes all the polarizing properties of a sample and, therefore, the optical differences between noncancerous and precancerous tissue that may be present within the matrix elements. A high-speed polarimetry system that generates 16 (4x4) full Mueller matrices to characterize tissues is presented. Feature extraction is done on the Mueller matrix elements resulting in depolarization and retardance images by polar decomposition. These are used to detect and classify early oral cancers and precancerous changes in epithelium such as dysplasia. These images are compared with orthogonal polarization images and analyzed in an attempt to identity useful factors for the differentiation between cancerous lesions and their benign counterparts. Our results indicate that polarimetry has potential as a method for the in vivo early detection and diagnosis of oral premalignancy.
[Show abstract][Hide abstract] ABSTRACT: Optical coherence tomography (OCT) is a new modality capable of cross sectional imaging of biological tissue. Due to its many technical advantages such as high image resolution, fast acquisition time, and noninvasive capabilities, OCT is potentially useful in various medical applications. Because OCT systems can function with a fiber optic probe, they are applicable to almost any anatomic structures accessible either directly, or by endoscopy. OCT has the potential to provide a fast and noninvasive means for early clinical detection, diagnosis, screening, and monitoring of precancer and cancer. With an imaging depth range of 2-3 mm, OCT diagnostics are particularly suitable for the oral mucosa. Currently, it is difficult to detect premalignant and malignant oral lesions due to their often multifocal nature and need for repeated biopsies. The goal of this study was to evaluate the feasibility of OCT for the diagnosis of multiple stages of oral cancer progression. In this paper, we present not only conventional 2-D OCT images, but also 3-D volume images of normal and precancerous lesions. Our results demonstrate that OCT is a potential tool for cancer detection with comprehensive diagnostic images.
IEEE Journal of Selected Topics in Quantum Electronics 08/2005; · 4.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The Mueller matrix describes all the polarizing properties of a sample, and therefore the optical differences between non-cancerous and pre-cancerous tissue should be present within the matrix elements. We present in this paper that a high speedpolarimetry system generates 16 full Mueller matrices to characterize tissues. Feature extraction is done on the Mueller matrix elements resulting in the depolarizance and retardance images by polar decomposition to detect and classify of early oral cancers and pre-cancerous changes in epithelium, such as dysplasia. These images are compared with orthogonal polarization image and analyzed in an attempt to determine the important factors for the identification of cancerous lesions from their benign counterparts. Our results indicate that polarimetry has potential as a method for the in vivo early detection and diagnosis of oral premalignancy and malignancy.