DaBlaCa-11: Photodynamic Diagnosis in Flexible Cystoscopy-A Randomized Study With Focus on Recurrence.

Objective: To examine whether photodynamic diagnosis (PDD) in addition to flexible cystoscopy in the outpatient clinic can reduce risk of tumor recurrence in patients with previous nonmuscle invasive bladder cancer. PDD is an optical technique that enhances the visibility of pathologic tissue and helps guidance tumor resection.

Methods: From February 2016 to December 2017, 699 patients from 3 urologic departments in Denmark were enrolled in a randomized controlled trial. Four months after transurethral resection of bladder tumor patients were randomized 1:1 to either an intervention group (hexaminolevulinate was instilled in the bladder before flexible cystoscopy with PDD video cystoscope) or a control group (white light flexible cystoscope), only. Primary endpoint was tumor recurrence within 8 months from the randomization. Secondary outcomes were numbers of procedures in general anesthesia, time to the first recurrence, differences in tumor size, risk of tumor progression, and identification of carcinoma in situ.

Results: A total of 351 patients were allocated to the intervention group (flexible PDD), and 348 to the control group (flexible white light). Throughout the following 8 months after randomization, only 117 patients in the intervention group had at least 1 tumor recurrence compared to 143 patients in the control group (P = .049). Odds ratio of 0.67 (P = .02, 95% CI: 0.48-0.95) correlates with a tumor reduction of 33% in favor of the intervention group.

Conclusion: Use of PDD in a routine surveillance cystoscopy first time after transurethral resection of bladder tumor for nonmuscle invasive bladder cancer reduces subsequent risk of tumor recurrence compared to WL cystoscopy alone.