Ultrasonic enhancement of cancer radiotherapy.

Ultrasound treatment (1.5 W/cm2, 1.9 MHz, C.W.) for 15 minutes either before or after x irradiation reduced the TCD50 of sarcoma-180 by approximately 40% while similar ultrasound treatment for up to 30 minutes did not reduce the TCD50 of the C3HBA mammary adenocarcinoma. Water bath heating (44.5 degrees C for 15 minutes) after x irradiation reduced the TCD50 of both tumors. Ultrasound alone for up to 30 minutes had no effect on growth or cure rate of either tumor.