Clinical relevance of narrow-band imaging in flexible cystoscopy: the DaBlaCa-7 study

OBJECTIVE: This multicenter study investigated whether the use of narrow-band imaging (NBI) in flexible cystoscopy could improve diagnostics to a degree where clinical management was relevantly changed.

MATERIALS AND METHODS: From May 2014 to June 2015, 955 patients were enrolled at three Danish urological departments. Patients had either hematuria (n = 483) or known recurrent non-muscle-invasive bladder cancer (NMIBC) (n = 472). High-definition (HD) cystoscopy was performed in white light (WL) and a preliminary clinical decision was made. Then, a second cystoscopy was performed in NBI and a conclusive clinical decision was made. A difference between the two decisions that had a clinical impact on the patient was considered clinically relevant.

RESULTS: Pathology was found in 216 WL cystoscopies, and additional pathology in 15 NBI cystoscopies (6.9%). Based on NBI, pathology was suspected in 23 patients (3.1%) in whom a WL cystoscopy revealed no tumor. In total, NBI changed the clinical decision relevantly in 1.9% of the patients. In hematuria patients, the calculated sensitivities of both NBI and WL were identically high, whereas sensitivity in patients with known NMIBC was significantly higher in NBI compared to WL (NBI: 100.0% vs WL: 83.2%, p < .05). NBI had a lower specificity compared to WL, especially in follow-up cystoscopies (NBI: 86.5% vs WL: 92.1, p < .05).

CONCLUSION: NBI can be a useful tool in clinical decision making as a supplement to WL because it yields a significantly higher detection rate than WL cystoscopy alone. This is particularly relevant in patients with known recurrent NMIBC.