The diagnostic value of narrow-band imaging for flat bladder lesions

Abstract

Objective To investigate the diagnostic value of narrow-band imaging for flat bladder lesions. Methods Forty-nine patients with flat bladder lesions diagnosed by white light cystoscopy + narrow-band imaging followed by transurethral resection were included. The diagnostic value of narrow-band imaging was evaluated based on postoperative pathological results. Results A total of 59 flat lesions were identified, in which 8 were normal urothelium, 3 were chronic inflammation, 1 was papillary urothelial neoplasm of low malignant potential, 1 were mild dysplasia, 1 was moderate dysplasia, 1 were severe dysplasia, 3 were carcinoma in situ, 16 were low-grade papillary urothelial carcinoma, 16 were high-grade papillary urothelial carcinoma, and 8 were invasive papillary urothelial carcinoma. For narrow-band imaging, the sensitivity was 86.7% (39/45), specificity was 57.1% (8/14), diagnostic accuracy was 79.7% (47/59), false-positive rate was 42.9% (6/14), positive predictive value was 86.7% (39/45), negative predictive value was 57.1% (8/14), area under ROC curve was 0.719. Among these lesions, the sensitivity and specificity for postoperative recurrent lesions were 100% (3/3) and 40% (2/5), respectively, and those for erythematous patch-like lesions were 90% (9/10) and 100% (4/4), respectively. Conclusion Narrow-band imaging can improve the detection rate for flat bladder tumor lesions, and reduce the risk for missed diagnosis under white light cystoscopy, especially for otherwise indistinguishable erythematous patch-like lesions. Key words: Bladder tumors; Flat bladder lesions; Flexible cystoscopy; Narrow-band imaging