Prospective evaluation of the performances of narrow-band imaging flexible videoscopy relative to white-light imaging flexible videoscopy, in patients scheduled for transurethral resection of a primary NMIBC.

Purpose: To evaluate on a lesion-by-lesion basis Narrow-Band Imaging flexible videoscopy (NBI-FV) in the detection of cancer compared to White-Light Imaging flexible videoscopy (WLI-FV).

Methods: WLI-FV and NBI-FV were sequentially performed in patients scheduled for TURBT for primary bladder cancer. Suspicious findings were individually harvested and characterized under WLI-FV (suspicious/non-suspicious) and NBI-FV (5-point Likert scale) and pathology. The primary objective was to determine if NBI-FV informed at least 20% more cancer lesions than WLI-FV (Relative true-positive rate > 1.19). A minimum of 120 specimens was to be analyzed to reach 90% power.

Results: Of 147 specimens taken in 68 patients, 101 were found suspicious under WLI-FV and 64 (64/101, 63.4%) confirmed as cancer. Of the 46 lesions undetected by WLI-VF, 16 were found positive for cancer (16/46, 34.8%). For NBI-FV, a significant increase in positive samples was observed with increments in Likert scale (p < 0.0002). Relative true-positive rate was 1.22 (95% CI 1.12-1.39)-NBI-FV detected 22% more cancer lesions compared to WLI-FV. Relative false-positive rate was 1.35 (95% CI 1.19-1.59).

Conclusion: Researching alterations in mucosa and microvasculature by narrow-band imaging flexible videoscopy augmented by 22% the detection of cancer foci and contributed to the objective of complete resection of all visible lesions. Conversely, it entailed a 35% increase in false-positive results compared to white-light imaging, although the structured analysis of narrow-band imaging findings might be used to grade suspicion according to the Likert scale and balance the risk of a false-positive result to the benefit of demonstrating cancer.