Spectroscopic measurement of diffuse reflectance for enhanced detection of bladder carcinoma* 1 (original) (raw)
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Spectroscopic measurement of diffuse reflectance for enhanced detection of bladder carcinoma
Urology, 1998
Objectives. To assess the diagnostic potential of diffuse reflectance spectroscopy for the detection of bladder carcinoma during cystoscopy. Our hypothesis is that neovasculature in neoplastic (dysplastic and malignant) regions will lead to a blood absorption "signature" that is different from that of normal tissue. Methods. Diffuse reflectance measurements have been performed in 14 patients undergoing mucosal biopsies or transurethral resection of a bladder tumor. A quartz optical fiber was advanced through the working channel of a cystoscope and placed in gentle contact with the bladder surface. A standard cystoscopy xenon light source was used for illumination and the reflectance spectra were recorded using an optical multichannel analyzer (OMA) system. From the spectra, the relative concentrations of hemoglobin (Hb), oxyhemoglobin (HbO2), oxygen saturation (HbO2%), and the total amount of blood (arbitrary units) were calculated to assess their usefulness in differentiating between neoplastic and benign bladder areas. Results. The spectra of 26 bladder areas (9 malignant areas including 4 carcinomata in situ, 2 dysplastic lesions, and 15 benign areas) have been analyzed. Only the total amount of blood was a useful parameter for the differentiation between neoplastic and benign bladder areas. The sensitivity, specificity, and positive and negative predictive values of this method for neoplastic tissue were found to be 91%, 60%, 63%, and 90%, respectively. Conclusions. The measurement of diffuse reflectance is a fast, simple, and noninvasive method which allows in vivo determination of bladder blood perfusion. The total blood concentration was increased in neoplastic bladder tissue, making it a tool for tissue diagnosis. The relatively low specificity is a result of inflammatory areas also exhibiting an increased total blood concentration. This pilot study encourages further studies to assess the usefulness of reflectance measurements for enhanced detection of bladder cancer. UROLOGY 51: [342][343][344][345] 1998. © 1998, Elsevier Science inc. All rights reserved.
Preliminary study of bladder cancer patients using spectral techniques
Journal of Optoelectronics and Advanced Materials
In the current study, we had obtained the spectral features of biomolecules of blood plasma, urine and bladder wash of a certain set of the patients of bladder cancer. The fluorescent biomarkers such as tryptophan, tyrosine, collagen, elastin, flavin and porphyrin, in the above body fluids are distinctly from those of normal controls. This study indicates the potential application of optical biopsy for bladder cancer detection.
Lund Reports in Atomic Physics, 1997
In this study three optical methods, autofluorescence, ALA-induced PpiX fluorescence and diffuse reflectance have been evaluated regarding their ability to detect malignant and dysplastic changes of human bladder tissue, in vivo. For the autofluorescence method, a single-fiber system based on a N2-laser was used. The 337 nm laser light excited the bladder tissue and the fluorescence was detected with an optical multichannel analyzer (OMA). The differences in the spectra from normal and malignant sites were investigated and the results showed a good demarcation between these tissue types. The sensitivity, specificity and positive and negative predictive values (non-malignant versus malignant) were found to be 73, 90, 73 and 90%, respectively. The second method utilized 5-aminolevulinic acid (ALA), which has a tendency to predominantly accumulate in malignant tissue. Through the heme cycle the ALA is converted to protoporphyrin IX (PpiX) which fluoresces red when excited with blue light. A filtered xenon-lamp was used to excite the PpiX and the red fluorescence was detected with a CCD camera mounted on a cystoscope. The images were stored on S-VHS tapes and the results were compared with the visual diagnosis made by the surgeon during the procedure as well as with the pathology report, if a biopsy of the site was taken. The easiness with which the PpiX is excited and the fluorescence detected, and the high tumor selectivity of ALA, make ALA-induced PpiX fluorescence a very helpful tool in finding tumors. The diffuse reflectance method utilized a white light source (xenon-lamp) and an OMA system to record the diffuse reflectance. By comparing the spectral differences between the malignant and non-malignant sites, a quantitative measure of the concentration of hemoglobin was obtained. In practice, this method showed only what was visible to the eye, that the tumor sites appeared red. Though, it provides a quantitative measure and avoids a subjective bias from the surgeon.
Urinary fluorescence analysis in diagnosis of bladder cancer
Neoplasma
Early diagnosis of bladder cancer is crucial for improvement of cancer specifi c survival and recurrence rate. We analyzed the possible role of fl uorescence urine analysis in bladder cancer diagnosis. Th e cohort consisted of 20 healthy controls, 40 patients with hematuria and 75 patients with hematuria and histologically proven bladder tumor. Synchronous fl uorescence spectra with a 70 nm wavelength diff erence were recorded for (1:1-1:128) urine dilutions. Concentration matrices of synchronous spectra (CMSS) were used to classify samples into tested groups. CMSS analysis allowed us to distinguish patients with tumor from patients with hematuria with a sensitivity 55% and specifi city 74.7%. Th is is comparable to the sensitivity and specifi city of other non-invasive tests like BTA stat and nmP-22 (Bladder check®). Lower fl uorescence intensity of Imax 280 nm and ratio of 280 nm to 450 nm was found to be associated with the presence of tumor. We have found an association of decreased fl uorescence with the stage of the disease. Our data suggest that CMSS urine analysis has a potential role in the non-invasive diagnostic tests for bladder cancer, but it cannot replace the current diagnostic algorithm yet.
Photodynamic diagnosis of bladder cancer in ex vivo urine cytology
Photonic Therapeutics and Diagnostics II, 2006
Bladder cancer is the fourth common malignant disease worldwide, accounting for 4% of all cancer cases. In Singapore, it is the ninth most common form of cancer. The high mortality rate can be reduced by early treatment following precancerous screening. Currently, the gold standard for screening bladder tumors is histological examination of biopsy specimen, which is both invasive and time-consuming. In this study ex vivo urine fluorescence cytology is investigated to offer a timely and biopsy-free means for detecting bladder cancers. Sediments in patients' urine samples were extracted and incubated with a novel photosensitizer, hypericin. Laser confocal microscopy was used to capture the fluorescence images at an excitation wavelength of 488 nm. Images were subsequently processed to single out the exfoliated bladder cells from the other cells based on the cellular size. Intensity histogram of each targeted cell was plotted and feature vectors, derived from the histogram moments, were used to represent each sample. A difference in the distribution of the feature vectors of normal and low-grade cancerous bladder cells was observed. Diagnostic algorithm for discriminating between normal and low-grade cancerous cells is elucidated in this paper. This study suggests that the fluorescence intensity profiles of hypericin in bladder cells can potentially provide an automated quantitative means of early bladder cancer diagnosis.
Photodynamic diagnosis of bladder cancer in ex vivo urine cytology
2006
Bladder cancer is the fourth common malignant disease worldwide, accounting for 4% of all cancer cases. In Singapore, it is the ninth most common form of cancer. The high mortality rate can be reduced by early treatment following precancerous screening. Currently, the gold standard for screening bladder tumors is histological examination of biopsy specimen, which is both invasive and time-consuming.
Fluorescence detection of bladder cancer using urine cytology
International Journal of Oncology, 2007
Bladder cancer is the fourth most common malignant disease worldwide, accounting for 4% of all cancer cases. In Singapore, it is the ninth most common form of cancer. The high mortality rate in bladder cancer can be reduced by early treatment following pre-cancerous screening. Currently, the gold standard for screening bladder tumors is histological examination of biopsy specimens, which is both invasive and time-consuming. In this study, ex vivo urine fluorescence cytology was investigated to offer an alternative timely and biopsy-free means for detecting bladder cancers. Sediments in patient urine samples were extracted and incubated with a novel photosensitizer, hypericin. Laser confocal microscopy was used to capture the fluorescence images at an excitation wavelength of 488 nm. Images were subsequently processed to single out the exfoliated bladder cancer cells from the other cells based on the cellular size. Intensity histograms of each targeted cell and feature vectors, derived from the histogram moments, were used to represent each sample. A difference in the distribution of the feature vectors of normal and low-grade cancerous bladder cancer cells were observed. A diagnostic algorithm for discriminating between normal and low-grade cancerous cells is elucidated in this report. This study suggests that the fluorescence intensity profiles of hypericin in bladder cells can potentially provide an automated quantitative means of early bladder cancer diagnosis.
Methods for bladder cancer diagnosis – The role of autofluorescence and photodynamic diagnosis
Photodiagnosis and Photodynamic Therapy, 2019
Highlights Bladder cancer is one of the most common malignant tumors in humans White light cystoscopy is the gold standard for detection of bladder cancer Autofluorescence (AFE) and photodynamic diagnostics (PDD) are the new techniques for early bladder cancer diagnosis High sensitivity and specificity of AFE/PDD in bladder cancer diagnosis