# Effect of extending the oral administration period of 5‐aminolevulinic acid on diagnostic accuracy and treatment outcomes for non–muscle‐invasive bladder cancer

## TL;DR

This study shows that extending the administration period of 5-aminolevulinic acid before bladder cancer surgery does not reduce diagnostic accuracy or treatment effectiveness.

## Contribution

The study demonstrates that extending 5-ALA administration time up to 8 hours before surgery maintains diagnostic sensitivity and improves recurrence-free survival.

## Key findings

- Fluorescent light mode had higher sensitivity (93.2%) compared to white-light mode (62.6%).
- Recurrence-free survival was significantly better in ALA-PDD groups compared to white-light groups.
- Extending 5-ALA administration time up to 8 hours did not reduce diagnostic accuracy.

## Abstract

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).

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.

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).

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.