ELECTROMOTIVE DIFFUSION (EMD) AND PHOTODYNAMIC THERAPY WITH DELTA-AMINOLEVULINIC-ACID (DELTA-ALA) FOR SUPERFICIAL BLADDER-CANCER

Recent reports have shown that topical application of delta-aminolaevu linic acid (delta-ALA) can be used for the photodynamic diagnosis and therapy of superficial bladder tumours. Electromotive diffusion (EMD) increases the cellular uptake of polar substances. In six patients wit h biopsy-proven recurrent carcinoma in situ of the bladder after Bacil lus Calmette-Guerin (BCG) treatment, 100 cm(3) of a 0.5% delta-ALA sol ution at pH approximate to 6 was instilled into the bladder. With a sp ecial Foley catheter containing a stainless steel electrode, EMD, with a 15 mA, pulsed current, positive polarity at the catheter, was creat ed for 20 min in the sedated patient. Thereafter a laser fibre with a spheric diffuser was inserted into the bladder over a cystoscope. The bladder surface was irradiated at a wavelength of 632 nm with 350 mW s (-1) (total dose, 30-50 J cm(-2)). Follow-up consisted of a cystoscopy and biopsy after 6 weeks and cystoscopy and cytology every 3 months t hereafter. The whole procedure was well tolerated. Currently, five pat ients are tumour free after a follow-up of 10-16 months. One patient h as recurred after 10 months with a Ta G3 superficial tumour at the bla dder neck which was resected. In a transwell cell culture model, we in vestigated the effect of delta-ALA treatment with and without applicat ion of EMD. In this in vitro system, application of an electric held s howed only a small increase in delta-ALA uptake compared with uptake b y passive diffusion.