Fluorescence detection of bladder cancer using urine cytology.
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.
School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore.
Chit Yaw
CY
Fu
Beng Koon
BK
Ng
Sirajudeen Gulam
SG
Razul
William Wei Lim
WW
Chin
Puay Hoon
PH
Tan
Weber Ko
WK
Lau
Malini
M
Olivo
D000873:Anthracenes; D001331:Automation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence / Q000295:instrumentation / Q000379:methods*; D015233:Models, Statistical; D010569:Perylene / Q000031:analogs & derivatives / Q000494:pharmacology; D017319:Photosensitizing Agents / Q000494:pharmacology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016482:Urinalysis / Q000379:methods*; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000652:urine*
D000873:Anthracenes; D017319:Photosensitizing Agents; D010569:Perylene; C004965:hypericin