PARENT SESSION
1:30 PM to 3:30 PM
Saturday, April 20, 2002
Poster Session 1 Noninvasive Treatment Monitoring and Treatment Planning
Room: Nevada 1-2

(MP01-5) Ultrasound properties of human prostate tissue during heating: implications for non-invasive monitoring of thermal therapy.

Worthington, Arthur¹, Sherar, Michael^*,1,2, ¹ Ontario Cancer Institute/Princess Margaret Hospital, Toronto, ON, Canada² Departments of Medical Biophysics and Radiation Oncology, Toronto, ON, Canada

ABSTRACT-
The objective of this project was to measure changes in the ultrasound properties of human prostate during heating to be used to develop ultrasound monitoring during minimally invasive thermal therapy for prostate cancer. The ultrasound attenuation coefficient and backscatter power of fresh human prostate tissue were measured as it was heated. Samples of human prostate were obtained directly from autopsies and heated quickly to final temperatures of 45C, 50C, 55C, 60C and 65C. A 5.0 MHz transducer was scanned in a raster pattern over the tissue and radio frequency data were collected at 36 uncorrelated positions. Both attenuation and backscatter were measured over the frequency range 3.5 to 7.0 MHz at each minute of a 30 min heating. Little change was discovered in attenuation or backscatter at 55C or less. The attenuation coefficient and backscatter power increased by factors of 1.25 and 5 respectively during the 60C heating. During the 65C heating, the same properties showed increases by factors of 2.7 and 9. These results indicate that it may be possible to employ real time transrectal ultrasound to monitor thermal therapy of the prostate.

KEYWORDS: ultrasound, properties, prostate, heating