CARTAS AL DIRECTOR/EDITOR

Dear colleague,

Many thanks to Prof. Dr. Ramon Abascal Garcia for his clear statement to fluorescence diagnosis of bladder cancer by 5- amino-levolinic acid (ALA). This method was developed on the Dept of Urology and the Laser Research Center of University of Munich - Grosshadern in 1990 under my supervision.

A supposed low specifity led to refusal of this method although sensitivity was about 98 %. Especially flat lesions and carcinomata in situ can be recognized by ALA - induced fluorescence: this is an important step in diagnosis as well as treatment of bladder cancer.

The false positive fluorescence after ALA-instillation is mainly evoked by inflammation of bladder mucosa. As we could see by spectralanalysis, this is a fluorescence from a other kind of porphyrine, however. Well trained endoscopists can also confirm that the fluorescences differ. But in our opinion, the different red - fluorescences are not so important because for confirmation - cancer or not- you need a biopsy in any case.

The story with ALA and light (xenon- or laserlight) is not yet finished: there are new fields e.g. in treatment of solid tumors and metastases after systemic ALA-application. The first results in treatment of brain - and prostate cancers are interesting.

Yours,

Univ. Prof. Dr. Alfons Hofstetter
Director of Dept. of Urology and Life-Research Center
University of Munich
Munich (Germany).