Detection of bladder dysplasia using 5-aminolaevulinic acid-induced porphyrin fluorescence

To report results of a clinical investigation on the detection of bladder dysplasia and in situ carcinoma by using fluorescence induced by 5-aminolaevulinic acid (ALA).

The study included 50 patients with a primary bladder lesion, who had a bladder instillation of 50 mL of 3% ALA solution >or= 1 h before transurethral resection of the tumour. Random biopsies were taken using white-light cystoscopy, then using blue light to induce fluorescence; positive zones were noted and biopsied. The primary lesion was then resected. The frequency of dysplasia detected by ALA-induced fluorescence was evaluated, as was the risk of recurrence with a follow-up of >or= 2 years.

In all patients the tumours were positive; in 21 fluorescence distant from the tumour was detected. The pathological report of the biopsies showed 11 cases of dysplasia, six of carcinoma in situ and four of inflammatory lesions. In 29 patients there was no fluorescence and quadrant biopsies were normal in all but three with moderate dysplasia. Within the minimum follow-up patients with bladder dysplasia detected by ALA-induced fluorescence had a higher risk of recurrence.

ALA-induced fluorescence of the bladder significantly enhanced the detection of dysplasia and in situ carcinoma. However, this technique requires further investigation using well-characterized instrumentation and study protocols to determine any effect on treatment choice.