Autofluorescence spectroscopy can improve the early detections of oral cancer. Biochemical and structural changes associated with dysplastic progression alter the optical properties of oral mucosa and cause diagnostically significant differences in spectra from normal and neoplastic sites. This dissertation describes experimental and modeling studies aimed at revealing biological reasons for the diagnostically significant differences observed in depth-resolved fluorescence spectra from normal and neoplastic oral mucosa. An experimental approach, based on high-resolution fluorescence imaging, is used to study the autofluorescence patterns of oral tissue. At UV excitation, most of the epithelial autofluorescence originates from cells occupying the basal and intermediate layers, while stromal signal originates from collagen and elastin crosslinks. With dysplasia, epithelial autofluorescence increases, while autofluorescence from subepithelial stroma drops significantly. Benign lesions also display a drop in autofluorescence from subepithelial stroma, but have different epithelium fluorescence patterns compared to dysplasia. Optical probes that measure mostly stromal fluorescence, may reveal a similar loss of fluorescence intensity and thus fail to distinguish benign inflammation from dysplasia. These results emphasize the importance of using probes with enhanced detection of epithelial fluorescence for improved diagnosis of different types of oral lesions. The second part of this work presents a Monte Carlo model that predicts fluorescence spectra of oral mucosa obtained using a depth-selective probe as a function of tissue optical properties. A model sensitivity analysis determines how variations in optical parameters associated with neoplastic development influence the intensity and shape of spectra, and elucidates the biological basis for differences in spectra from normal and premalignant oral mucosa. Spectra of oral mucosa collected with the depthselective probe, are affected by variations in epithelial optical properties and to a lesser extent by changes in superficial stromal parameters, but not by changes in the optical properties of deeper stroma. Changes in parameters associated with dysplastic progression lead to a decreased fluorescence intensity and a shift of the spectra to longer emission wavelengths. Decreased fluorescence is due to a drop in detected stromal photons, whereas the shift of spectral shape is attributed to an increased fraction of detected photons arising in the epithelium.

This dissertation focuses on the development of algorithms for analyzing and modeling of the signals from optical spectroscopy. This dissertation is motivated by the detection of oral cancer, but some of the methods developed can be generalized to epithelial cancers of other sites. Two main topics are covered in this dissertation: Analysis and Modeling. For analysis, the focus is on developing algorithms to make diagnostic predictions. The analysis methods are empirically tested using an oral cancer dataset. Statistical analyses show that polarized reflectance spectroscopy has the potential to aid screening and diagnosis of oral cancer. Also, a novel adaptive windowing technique is developed to extract spectral features with fewer windows that retain the diagnostic information. For modeling, a Monte Carlo model simulating light-tissue interactions is presented to aid in the design of diagnostic instrumentation. / text

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The potential applicability of Fourier transform infrared (FM) spectroscopy for the study of biomolecules, has been investigated through the investigation of three specific applications. Two of the applications selected involve the classification of whole cells, whereas the third concerns the study of peptides and proteins isolated from tissues as well as synthetic peptides. In the microbiological application, for the differentiation of bacteria on the basis of their FTIR spectra, it has been found that classification is most efficiently achieved through the utilisation of artificial neural networks, and that a wide, variety of bacteria can be correctly identified with minimal sample preparation after being grown on a single growth medium. The suitability of low-cost, disposable materials as supports for the deposition of bacteria samples has also been demonstrated. In contrast to the successful classification of bacteria, it has been found that the examination of cytological smears by FTIR spectroscopy does not allow the classification of cervical cell populations into the recognised diagnostic categories. In a microscopic investigation of the same cell populations utilising infrared imaging, localised areas of the smear were found to exhibit distinct characteristics not observed in the spectra of the entire population. This indicates that infrared imaging system may be required for this type of application because the infrared spectrum recorded from a whole cervical smear does not allow the detection of the small spectral features arising from the molecular changes associated with a localised pathological state. Finally, the investigation of factors affecting the stability of peptides related to amyloidosis has shown that temperatures above 70°C, hydrostatic pressure greater than 6 kbar, and alkaline pH promote the disaggregation of the typical intermolecular beta-sheet structure of amyloid peptides. Peptides utilised as model systems for amyloidosis showed

There is considerable evidence that delays in diagnosing and treating breast cancer reduce long-term survival. The purpose of this study was to assess the waiting time between diagnosis and treatment for Alberta women with breast cancer and to examine the influence of age, cancer stage, Regional Health Authority (RHA), community size, and year of diagnosis on this time interval. The data were obtained from the Alberta Cancer Board. The information included approximately all Alberta women with breast cancer between 1997 and 2000. The overall median waiting time was 17 days. The mean and median delay increased by an average of two days each year. Only 43.8% of cases were treated within the recommended 14 days. The delay was significantly longer for women younger than 70, with stage 1 disease and from Northern RHAs. Efforts must be made to decrease delay and ensure that all women receive equal access to health services. / xii, 106 leaves : ill. ; 28 cm.

Despite the availability, accessibility and affordability of cervical cancer screening (CCS) in Malawi, many women do not utilize the CCS services. This research was conducted in Blantyre district, Malawi. The main objective of the study was to identify factors that act as barriers to the uptake of cervical cancer screening programs among urban and rural women in the Blantyre district of Malawi. A quantitative design was used and convenience sampling was applied in selecting a sample of 196 women from the population of women aged 18 and over in two Reproductive Health clinics, one urban clinic at Queen Elizabeth Central Hospital and one rural clinic at Mlambe hospital in Blantyre district, Malawi. A structured questionnaire was used to collect data. The questionnaire was translated from English into the local Chichewa language so that respondents were interviewed and responded in a language that they were able to comprehend. Analysis and discussion of findings are presented in five sections. Data were processed into numeric values using SPSS version 15.0 and Microsoft Excel to give meaning to the findings of the study. In order to test for statistically significant associations between variables, the Pearson correlation was applied. The study revealed that the main barrier to CCS was that women lack knowledge and information about cervical cancer and there is a lack of publicity about CCS services. Lack of knowledge was found in relation to - risk factors, prevention of, detection of and benefits of cervical cancer screening with a greater knowledge deficit being found in the rural women. Higher levels of education in both the urban and rural groups did not have a positive influence on the screening behaviours of the women. Commencing sexual intercourse at ages 15 to 19 years and having multiple sexual partners were the main risk factors to cervical cancer among the women in the study. It was also found that although rural women perceived themselves being very likely to be at risk of cervical cancer, this perception did not translate into CCS behaviour. v / Thesis (M.A.)-University of KwaZulu-Natal, Durban, 2009.

This research is a follow up of a "Breast Week" which was organized in Freetown, Sierra Leone. The specific objective of this study was to assess the effectiveness of the knowledge and teachings given to the women who participated in this project. The unrecorded cases of breast lumps and breast cancer observed in women in Sierra Leone prompted the researcher to undertake this present study. A quantitative approach was adopted and a structured interview schedule and an observational checklist guided the data collection process. A sample size of 120 women (10%) who participated in the "breast week" was obtained through systematic sampling. The first part of the study involved assessment of the theoretical background of the research topic followed by the second phase during which the women demonstrated Breast Self-Examination to detect abnormalities of the breasts. Discussions and analysis of the findings are presented in three sections. Texts from open ended questions were categorized and explained in numerical terms as the study was quantitative in nature. The data was processed through use of SPSS and Microsoft Excel. Frequency counts were applied to the data, use of non-parametric tests on the number of women who practiced Breast Self-Examination before and after the breast week showed a statistically significant difference in the number of women now practicing BSE as a screening method for breast cancer after receiving the health education. It was found that the majority of the women linked breast cancer to the signs and symptoms associated with it and were able to describe the disease as one that kills women if not promptly detected and/or treated appropriately. Findings indicate that the majority of the women (78.3%) had previously had mmor breast problems. An assessment of the effectiveness of knowledge on breast cancer showed that these women could identify breast cancer as a disease that affects women and may cause deaths if not detected on time or treated promptly. These women were able to demonstrate to the researcher how they examine their breasts to exclude abnormalities. Three women had breast lumps detected through examination of the breasts during the breast week. Two of them had had the lumps removed and are currently on medication. One of the women who had a breast lump detected was financially constrained and could not afford the cost of surgery. The number of women who can now perform BSE increased (95.0%) after having the knowledge on breast cancer and BSE. The majority of the women (97.4%) received information on how to examine their breasts for breast cancer through the information provided during the breast week. It is thus concluded that the objectives of the breast week were met. / Thesis (M.N.)-University of Natal, Durban, 2004.

Magnetic Resonance Elastography (MRE) is an emerging method for non-invasive breast cancer screening. It takes the MRI displacement data output and reconstructs the internal stiffness distribution, where cancerous tissue is approximately five to ten times stiffer than healthy breast tissue. Hence, MRE offers a high contrast solution to this diagnostic problem. Current MRE methods for reconstructing stiffness use forward simulation based optimization methods that are highly non-linear, non-convex and very heavy computationally. This research develops integral-based inverse problem solutions that reformulate the underlying differential equations in terms of integrals of MRI measured displacement data, and this transforms the problem into a linear, convex optimization. All derivative terms in the formulation are removed by special choice of integration limits, so no smoothing or filtering of the input data is required. The resulting equations can easily be solved by linear least squares requiring very minimal computation. 1D inverse algorithms were developed to provide a proof of concept of the integral-based method. Initially, the complete compressible 2D Navier's equations were used to develop the 2D inverse methods. Reasonable results were achieved with the algorithm successfully identifying a 1cm by 1cm tumour with up to 10% noise, data resolution of 20 measured points per cm and actuation frequencies of 100Hz. However, for the same input data set, a simplified incompressible 2D model was used as the basis for the final proposed inverse algorithm. This approach significantly improved results by removing ill-conditioned terms from the original formulation. For a 1cm by 1 cm tumour, accurate results were obtained with up to 40% noise, a range of actuation frequencies and very low data resolution of the order of 2 measured points per cm. These results thus indicate that more crude and less expensive data measurement systems could be used to obtain good results. The methods developed can be readily extended to 3D by applying a similar incompressible integral formulation to the 3D Navier's equations.

The Application of Magnetic Resonance (MRI) and Computed Tomography Imaging (CT) in the Diagnosis and Management of Maxillofacial Tumours. For decades maxillofacial surgeons over the world have been frustrated by the high and often fatal recurrence of certain advanced jaw tumours. This study conclusively proves that Computed Tomography and especially Magnetic Resonance Imaging significantly decreases recurrence of Odontogenic Keratocyst and Ameloblastoma and allows surgical planning to avoid these recurrences. / Doctor Scientiae (Odontology) - DSc(Odont)

The main objective of this master’s thesis is to investigate the possibility of applying spatially-filtered continuous-wave acoustic tomography to the detection of breast cancer. A continuous acoustic wave is transmitted through the specimen in this tomographic imaging method. Any scattered waves that do not positively contribute to the projection are filtered out using an aperture. There is evidence to suggest that cancerous lesions in the breast have a higher speed of sound than surrounding tissues. This imaging method produces two tomograms of the specimen simultaneously: one showing the internal speed of sound, and the other showing the internal acoustic attenuation coefficient. There is the possibility for a third imaging modality, acoustic dispersion tomography, to be applied to this imaging method. Two proof-of-concept prototype spatially-filtered continuous-wave acoustic tomography scanners were designed and built: one that uses a collimated beam to interrogate the specimen, and another that uses a confocal beam. A least-squares tomographic reconstruction algorithm was chosen to reconstruct the tomograms this method creates. A prostate phantom and a breast phantom were imaged with the confocal tomographic scanner. The tomograms of the prostate phantom show two 1 cm lesions which are consistent with information from the phantom manufacturer. Further work is required to properly validate the speed of sound and acoustic attenuation measurements this method produces. / Graduate