Efficacy of photodynamic diagnosis for non-muscle invasive bladder cancer: Exploratory subject-based analysis in a prospective, single-arm, multicenter phase III trial

Background: This analysis utilized a subject-based analysis of data from the prospective single-arm phase III trial (jRCT2061210055) to evaluate the efficacy of photodynamic diagnosis (PDD) when 5-aminolevulinic acid hydrochloride (5-ALA) was administered 4–8 h before transurethral resection of bladder tumors (TURBT). Methods: This study evaluated 144 patients suspected of having non-muscle invasive bladder cancer (NMIBC), including 127 with NMIBC (38 patients had normal-to-flat-appearing cancer) and 17 without cancer. The diagnostic accuracy and clinical utility of blue light (BL) during TURBT were assessed for each patient and compared with those of white light (WL). Results: Subject-based analysis revealed that WL alone missed tumor lesions in 33.1 % of patients, whereas BL alone missed 3.1 % in a biopsy-based analysis (P < 0.001). WL alone failed to diagnose NMIBC in 4.7 % of patients, while BL missed 1.6 %. Adding BL to WL led to an upgrade of NMIBC risk classification in 12 of 127 patients (9.4 %), including 5 upgraded to high-risk and 4 to highest-risk categories. Conclusion: This study is the first to demonstrate that PDD's efficacy is maintained up to 8 h after oral 5-ALA administration and indicates that PDD improves the detection rate of bladder cancer, potentially optimizing risk stratification and offering optimal additional treatment.