Narrow-band imaging flexible cystoscopy in the detection of recurrent urothelial cancer of the bladder

OBJECTIVE To investigate whether narrow-band imaging (NBI) flexible cystoscopy improves the detection rate of urothelial carcinomas (UCs) of the bladder. NBI is an optical image enhancement technology in which the narrow bandwidth of light is strongly absorbed by haemoglobin and penetrates only the surface of tissue, increasing the visibility of capillaries and other delicate tissue surface structures by enhancing contrast between the two. PATIENTS AND METHODS Between November 2005 and May 2007 at the Queen Elizabeth Hospital, Birmingham, NBI flexible cystoscopy was performed on 29 patients with known recurrences of UC of the bladder after initial conventional white-light imaging (WLI) flexible cystoscopy with the same instrument (Olympus Lucera sequential RGB endoscopy system). RESULTS Subjectively, NBI provided a much clearer view of bladder UCs and in particular their delicate capillary architecture. Objectively, NBI detected 15 additional UCs in 12 of 29 patients (41%), as compared with WLI. The mean (SD) difference was 0.52 (0.74) UCs per patient (P < 0.001, Wilcoxon signed-rank test). CONCLUSIONS Even in the few patients studied there is strong evidence that NBI differs from WLI in the number of UCs it detects, with a significantly increased detection rate. We feel that further evaluation of NBI flexible cystoscopy in more patients will show this technique to be highly valuable in the detection of both new and recurrent bladder UCs, and this work is continuing in our unit.