A kit comprising: a urinary catheter comprising a first and a second longitudinal lumens an ultrasonic transducer disposed about said catheter a balloon mounted on said catheter, and enclosing said transducer and a reservoir containing an acoustic coupling medium, wherein: said catheter further comprises a first opening in said first longitudinal lumen, said first opening disposed inside said balloon and configured to inflate said balloon with at least some of said acoustic coupling medium, said catheter further comprises a second opening in said second longitudinal lumen, said second opening disposed outside said balloon and configured to deliver a therapeutic fluid into the urinary bladder, around said balloon, and activation of said transducer in said urinary bladder causes cavitation bubbles to form in said therapeutic fluid adjacent an internal surface of the urinary bladder, and little or no cavitation bubbles are formed in said acoustic coupling medium in said balloon.