Abstract
OBJECTIVES: To evaluate the treatment outcomes of 5-aminolevulinic acid hydrochloride (5-ALA) photodynamic diagnosis (PDD)-assisted transurethral resection of bladder tumour (TURBT) (ALA PDD-TURBT, hereinafter referred to as 'ALA-PDD') exceeding 4 h after ALA administration for non-muscle-invasive bladder cancer (NMIBC). PATIENTS AND METHODS: This retrospective single-centre study included 386 patients who had undergone TURBT with or without 5-ALA for NMIBC between January 2018 and December 2024. Patients who received 5-ALA were divided into two groups based on 5-ALA exposure times before TURBT: 2-4 h and 4-8 h groups. The diagnostic sensitivity and specificity of procedures performed after the two exposure times were calculated by comparing cystoscopy findings with pathological findings in the ALA-PDD group. Recurrence-free survival (RFS) and progression-free survival (PFS) rates of NMIBC patients in the white-light (WL) and ALA-PDD groups were examined using Kaplan-Meier curves. RESULTS: When the same lesion was evaluated using WL and fluorescent light (FL) modes, the sensitivity was 62.6% for the former and 93.2% for the latter. Furthermore, when the FL mode was divided into two ALA-PDD groups, the sensitivity was 93.9% in the 2-4 h group and 91.3% in the 4-8 h group (p = 0.29). On the other hand, RFS was significantly longer in both the 2-4 h and 4-8 h ALA-PDD groups than in the WL group (p < 0.05), with no significant difference in RFS between the 2-4 h and 4-8 h ALA-PDD groups (p = 0.105). CONCLUSION: The clinical efficacy of ALA-PDD, in terms of sensitivity and recurrence, was maintained even when the 5-ALA administration time was extended from 2 to 4 h to 2-8 h prior to TURBT.