X-Ray Inactivation of Cultured Mammalian Cells: Enhancement by Ultrasound

Abstract

Ultrasound (0.14 W/cm2, 920 kHz) was found to decrease the dose of 50-kVp x rays required to prevent 99% of cultured M3-1 Chinese hamster cells from forming colonies by a factor of 1.3 when delivered during the first 10 minutes after irradiation. Ultrasound alone had no detectable effect. Postirradiation heating for 10 minutes at the maximum temperature tolerated by the cells (42°C) had no detectable effect on radiation dose-survival curves.