Novel Therapeutic Applications of Ultrasound. Utilization of Thermal and Cavitational Effects.

Biophysical modes of action of ultrasound are classified as thermal and non-thermal effects. Non-thermal effects of ultrasound include cavitational and non-cavitational effects. The thermal effects of ultrasound have already been used for hyperthermic cancer therapy as well as microwaves and radiofrequency heating. Recently among the non-thermal effects of ultrasound, acoustic cavitation is considered to have the highest potential for therapeutic applications. Many examples of therapeutic applications for which cavitation may be involved have been reported, including sonodynamic therapy, gene therapy, thrombolysis and the use of microbubbles for enhancing ultrasonic action. This subject is of interest because it is related to the development of novel therapeutic applications using ultrasound. The role of cavitational effects in the therapeutic use of ultrasound is reviewed.