Introduction: Early detection of bladder carcinoma is very important clinical problem. Diagnostic yield of white light cystoscopy with random biopsies remains poor. The use of exogenous fluorescence significantly increases the sensitivity, but specificity remains low. We analyzed diagnostic efficacy of OCT during white light cystoscopy and combined use of OCT and fluorescence cystoscopy.
Materials and methods: An OCT device (1280 nm wavelength with 3 mW power, 8 Fr endoscopic probe, in-depth resolution 15 μm in tissue, lateral resolution 30 μm, acquisition time 1.5 sec for a 200x200 pixels image) was used in combination with a standard Karl Storz fluorescence cystoscope. A 3% solution of 5-ALA was instilled intravesically for 2 hours before the procedure. Initial examination was made under white light. OCT imaging and biopsy of all fluorescence zones were performed in blue light. 20 patients were studied. The study is ongoing.
Results: 80 fluorescence zones (16 exophytic and 64 flat lesions) were analyzed with OCT. All exophytic zones were correctly detected by OCT and white light cystoscopy. Out of 64 flat fluorescent areas, 56 had benign histopathology readings, with 45 of them having the benign type of OCT images. Of 8 fluorescent zones with neoplastic histopathology, OCT correctly detected all 8. Based on this preliminary data, OCT could help to avoid 80% of unnecessary biopsies/resections.
Conclusion: Combined use of OCT imaging and fluorescence cystoscopy can substantially improve diagnostic yield of bladder neoplasia detection.