Evaluation of Spectra A and B Modes in Diagnosis of Suspicious Bladder Lesions.

Background

White light imaging (WLI) cystoscopy, a "gold standard" for diagnosis of nonmuscle invasive bladder cancer (NMIBC), can miss ∼25% of bladder cancers. Spectra A (SA) and Spectra B (SB) are virtual optical chromoendoscopy modes introduced by Storz.

Objective

To evaluate whether SA and SB improve over WLI in diagnosis of NMIBC. Design, Setting, and

Participants

Storz Professional Image Enhancement System (SPIES) modes allow side-by-side viewing of WLI and spectra images. Cystoscopy images of some patients with suspected NMIBC and some normal cystoscopy findings were cut in two parts: one WLI and the other SA or SB. Each individual image was sent to the 3721 members of Urological Society of India separately through online survey. Histologic diagnosis was considered final diagnosis. Intervention: The observers were asked whether they considered the image to be cancer; yes, no, or cannot say were the three response options. Outcome Measures and Statistical Analysis: Primary outcome measure was improved diagnosis of NMIBC. Diagnostic efficacy was analyzed through 2 × 2 tables, McNemar test, and Fleiss Kappa. Results and Limitations: A total of 273 observers participated in the study. The sensitivities of WLI, SA, and SB were 89.81, 91.15, and 88.81, respectively. The specificities were 73.18, 66.17, and 68.68, respectively. In patients with cancer, both SA and SB improved the diagnostic efficacy of WLI. SA added significantly to the diagnostic accuracy over WLI (χ2 = 12.23, p = 0.00046). SB also added significantly over WLI (χ2 = 11.76, p = 0.0006). With increasing cancer grade, the sensitivity and negative predictive value of all modes increased. The major limitation of this study is the online diagnosis based on still images.

Conclusions

In patients with cancer, SA and SB significantly add to the diagnostic accuracy of WLI. As compared with the negative WLI, if SA and SB are negative, NMIBC would be less likely.