An ultrasonic therapy system delivers ultrasonic therapy energy to a therapy site in the body which is infused with microbubbles. A system without an image guidance capability has an array transducer which delivers therapy energy, a therapy transducer driver which causes the array transducer to deliver therapeutic energy, a control for controlling the intensity of the therapeutic energy, and a display of the sonotherapy signal strength of the energy and the concentration of microbubbles at the therapy site. A system with ultrasonic imaging capability will display an ultrasound image for therapeutic guidance and a measure of the microbubble concentration. The method of the present invention is performed as an adjunct to a standard drug therapy or other treatment regimen, following such treatment with an infusion of ultrasound and delivery of ultrasound therapy energy.