Early Photodynamic Diagnosis Cystoscopy After Bacillus Calmette-Guérin (BCG) Induction for High-Risk Nonmuscle Invasive Bladder Cancer Significantly Increased the Detection of BCG Refractory Tumors.

Objectives: To compare the detection rate of Bacillus Calmette-Guérin (BCG) refractory tumors between white light cystoscopy (WL-C) and Photodynamic Diagnosis cystoscopy (PDD-C). Materials and Methods: We performed a monocentric retrospective study that included all consecutive patients with high-risk nonmuscle-invasive bladder cancer (NMIBC) diagnosed from January 2017 to January 2021. All patients had an initial transurethral resection of bladder tumor (TURBT) with photodynamic diagnosis ± restaging TURBT if needed, followed by full-dose BCG induction. Within 8 weeks following BCG induction, all patients had both WL-C and PDD-C under general anesthesia ± TURBT in case of suspicious lesion. The primary end point was the detection of bladder cancer (BC) at post-BCG cystoscopy. Results: A total of 136 consecutive patients met inclusion criteria. Initial BC characteristics were: 35.6% of T1 tumor, 92.6% high grade, and 48.6% associated CIS. BC was diagnosed in 33/136 cases (24%) at early PDD-C after BCG induction: 77% Ta, 23% T1, 56% associated CIS, 68% high grade, and 6% muscle-invasive bladder cancer. Sensibility and Specificity of WL-C and PDD-C: 41% vs 91% (p < 0.001) and 86% vs 75% (p = 0.001). PDD-C detected 16 additional tumors: 81.3% Ta, 18.7% T1, 75% associated CIS, and 75% high grade. Conclusions: Systematic use of PDD after BCG induction increased the detection of BCG-refractory tumors and led to significant modification in the treatment of high-risk NMIBC. Future studies are needed to evaluate long-term oncologic benefit of early PDD reevaluation and its cost-effectiveness.