Caring for pregnant patients with breast cancer.
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Biomedical subjects
Andrea Milbourne
Publications and source records attributed to Andrea Milbourne.
Results of a pilot study of multispectral digital colposcopy for the in vivo detection of cervical intraepithelial neoplasia.
OBJECTIVE: Fluorescence spectroscopy is a promising technology for the detection of cervical squamous intraepithelial precancers and cancers. To date, many investigators have focused on point spectroscopy as an adjunct to diagnostic colposcopy. A device that visualizes the whole field of the cervix is needed for screening. To that end, we have developed a multispectral digital colposcope that works through the colposcope to image with white light, UV excitation at 345 nm, and blue light at 440 nm excitation. Here, we report the pilot study that precedes a Phase I trial. METHODS: The MDC system is composed of a light source, a colposcope, and a video rate color CCD camera with a frame grabber and takes approximately less than 1 min to make images of the cervix. Patients were measured at baseline and after acetic acid placement with white light, 345 nm excitation, and 440 nm excitation from the xenon arc lamp. The white light is in the visible spectrum, 345 nm excitation is in the UV spectrum and is not visible, and 440 nm excitation is blue light in the visible spectrum. White light generates a pink image of the cervix. 345 nm excitation, the UV light, excites fluorophores to emit a blue image. 440 nm excitation, the blue light, excites fluorophores to emit a green image. The patients underwent a loop excision procedure and the histopathology was inked and cut into 12 sections by the study pathologists. The histopathologic slides were scanned and the images were then reconstructed into maps. A diagnostic algorithm was calculated. The data were preprocessed, transformed, and analyzed by the K-means clustering method. Disease maps were generated using the algorithm and classifier and compared to white light colposcopy and the blue and green images obtained at 345 and 440 nm. RESULTS: Forty-six patients were measured at four clinical sites. Images were made of the cervix with white light, 345 nm excitation, and 440 nm excitation and are presented in the figures. As the study went on, images improved with improvements in the instrument. The white light and fluorescence images are presented with crudely constructed histopathologic maps and algorithmic maps. At 345 nm excitation, the UV light, histologically confirmed CIN appears darker blue; while at 440 nm excitation, the blue light, histologically confirmed CIN appears lighter green. CONCLUSIONS: This pilot study shows that MDC images can be matched to both histopathologic and algorithmic maps. The device and the algorithm are evolving but show promise. A Phase I trial is planned.
Adult↗
Diffuse reflectance patterns in cervical spectroscopy.
OBJECTIVES: Our laboratory seeks to develop minimally invasive cost-effective methods to improve screening and detection of curable precursors to cervical cancer. Previously, we have presented pilot studies that assess the diagnostic power of auto-fluorescence and diffuse reflectance spectroscopy. In the present study, we evaluate diffuse reflectance spectra from a comprehensive 850 patient clinical trial to determine its ability to discriminate normal tissue from several grades of abnormal cervical tissue. METHODS: Diffuse reflectance spectra at four source detector separations measured from 549 cervical sites were available for analysis. Three classifiers were implemented: one used spectral data directly as input, a second used simple spectral features such as peak position and intensity, and one used principal component analysis for feature selection. Algorithms were developed and evaluated using leave-one-out cross-validation to classify normal and precancerous cervical tissue. The percentage of samples correctly classified was used to evaluate and compare the performance of the algorithms, as compared to histology. RESULTS: Diffuse reflectance spectra of cervical precancer showed consistent differences from that of normal tissue at all source detector separations; reflectance intensity of precancer was lower than that of normal tissue on average. Normal cervical tissue spectra show more intensity variation between patients than other tissue grades. Reflectance spectra acquired from the closest source detector separations consistently demonstrated the most relevant information for tissue classification. Two persistent spectral patterns demonstrated that the contribution of hemoglobin absorption and the wavelength-dependent spectral slope contained relevant information for classification. CONCLUSIONS: Spectral patterns in diffuse reflectance spectra can be used for the discrimination of normal cervical tissue from low grade and high grade squamous intraepithelial lesions.
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