Ultrasonic treatment of tumors-III high intensity, low frequency exposures

Abstract Hamster fibrosarcomas were exposed to 1.06 MHz ultrasound at intensities of 90 W/cm 2 in a pulse mode (0.1 sec on, 0.9 sec off) to avoid excessive heating. Tumor temperatures ranged from 19 to 30°C during these exposures. The treatment had no apparent effect on the rate of growth of the primary tumor or on the rate of metastasis.