A Pilot Study of Low-Cost, High-Resolution Microendoscopy as a Tool for Identifying Women with Cervical Precancer
ABSTRACT Cervical cancer remains one of the leading causes of death among women in developing countries. Without resources to support Pap smear cytology and colposcopy, cost-effective approaches which enable single-visit "see-and-treat" protocols offer the potential to reduce morbidity and mortality due to this preventable disease. We carried out a pilot clinical study in Shanxi province, China, to evaluate a low-cost, high-resolution microendoscope (HRME) imaging system which enables evaluation of epithelial cell morphology in vivo. HRME images were obtained at discrete sites on the cervix in 174 women, in addition to visual inspection with acetic acid (VIA) and colposcopic examination. Of 69 sites appearing abnormal on colposcopy, only 12 showed high-grade disease (CIN2+) on pathology. Quantification of the nuclear-to-cytoplasm ratio by HRME enabled an ad hoc threshold to be defined, which correctly classified all 12 sites as abnormal, whilst classifying 38 of the remaining 57 pathology normal sites as normal. All patients with biopsy confirmed high-grade disease also tested positive for high-risk human papilloma virus (HPV) DNA and were classified as abnormal by HRME. Among the remaining patients who tested positive for HPV but were either normal by colposcopy or showed <CIN2 on pathology, only 6 of 32 (18.8%) were classified as abnormal by HRME.Visual examination techniques for cervical cancer screening may overestimate the prevalence of precancerous lesions, leading to unnecessary treatment, expense, and patient stress. The results of this study suggest that evaluation of suspicious lesions by HRME may assist in ruling out immediate cryotherapy, thus increasing the efficiency of current see-and-treat programs. Cancer Prev Res; 1-7. ©2012 AACR.
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ABSTRACT: For this tribute to Mario Sideri, we reviewed some of the current issues in colposcopy, many of which we were researching with him. The review concentrates on the impact of HPV testing on cervical screening, specifically on the practice of colposcopy as the major diagnostic procedure in cervical screening programmes. Topics include the changing population of women referred to colposcopy, evolving views of the colposcopic impression, differing approaches to directed and random biopsy, issues in teaching colposcopy using static images, and the development of colposcopy aids, and simplified visual assessment techniques.ecancermedicalscience 04/2015; 9. DOI:10.3332/ecancer.2015.530 · 1.20 Impact Factor
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ABSTRACT: In order to diagnose cancer in breast tissue, a sample must be removed, prepared, and examined under a microscope. To provide an alternative to conventional biopsies, an endomicroscope intended to perform optical biopsies is demonstrated. The system provides high resolution, high contrast images in real-time which could allow a diagnosis to be made during surgery without the need for tissue removal. Optical sectioning is achieved via structured illumination to reject out of focus light. An image is relayed between the sample plane and the imaging system by a coherent fiber bundle with an achromatized objective lens at the distal tip of the fiber bundle which is the diameter of a biopsy needle. The custom, plastic objective provides correction for both the excitation and emission wavelengths of proflavine (452 nm and 515 nm, respectively). It also magnifies the object onto the distal tip of the fiber bundle to increase lateral resolution. The lenses are composed of the optical plastics Zeonex E48R, PMMA, and polystyrene. The lenses are fabricated via single point diamond turning and assembled using a zero alignment technique. The lateral resolution and chromatic focal shift were measured and in vitro images of breast carcinoma cells stained with proflavine were captured. The optical biopsy system is able to achieve optical sectioning and to resolve smaller features than the current high resolution microendoscope.Conference on Endoscopic Microscopy VIII; 03/2013
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ABSTRACT: Objective: To investigate the concordance between optical images obtained with high-resolution microendoscopy (HRME) and conventional histopathology for ex vivo cholesteatoma specimens and surrounding middle ear epithelium. Methods: After resection of cholesteatoma and surrounding middle ear epithelium from surgical patients, tissues were stained with a contrast agent, proflavine, and the HRME fiberoptic scope was placed directly on each tissue specimen. 4- 10 short movie clips were recorded for both the cholesteatoma and surrounding middle ear epithelium specimens. The imaged areas were sent for standard histopathology, and the stained specimens were correlated with the HRME images. IRB approval was obtained, and each patient was consented for the study. Results: Ten cholesteatoma specimens and 9 middle ear specimens were collected from 10 patients. In each case, cholesteatoma was easily discriminated from normal middle ear epithelium by its hyperfluorescence and loss of cellular detail. Qualitative analysis for concordance between HRME images and histological images from the same surgical specimen yielded a strong correlation between imaging modalities. Conclusions: Keratinizing cholesteatoma and surrounding middle ear epithelium have distinct imaging characteristics. Loss of cellular detail and hyperfluorescence with proflavine are the hallmark characteristics of cholesteatoma which allow for differentiation from normal middle ear epithelium. Real-time optical imaging can potentially improve the results of otologic surgery by allowing for extirpation of cholesteatomas while eliminating residual disease. We anticipate performing an in vivo study to test this hypothesis.Conference on Photonic Therapeutics and Diagnostics IX; 03/2013