[Dosimetry of the neodymium-YAG laser endovesical irradiation of bladder tumors. Animal experiments (author's transl)].

Therapy of urinary bladder tumors with the aid of the Neodymium-YAG-laser is improved by two following demands. A homogeneous, deep necrosis must be obtained for the tumor cells to be devitalised completely, and neighbouring organs must be protected adequately. Both depth and shape of the necrosis were determined on liver tissue at different conditions, e.g. laser application with air, water and various time/power ratios. Measurements of temperature profiles at the bladder back wall reveal that the parameters necessary for sufficient transmural destruction of bladder tumors do not affect neighbouring organs. In clinical application it is not necessary to control temperatures occurring at the bladder wall during irradiation by means of temperature probes. It is sufficient to adjust the dosis of laser on the basis of superficial, visual discoloration. Carbonisation should be avoided by all means. Comparable effects were obtained by clinical application of data obtained during animal experimentation.