Image-guided ultrasound potentiated therapies
Among the most desirable replacements for invasive surgery is the use of focused ultrasound beams to coagulate or destroy tissue. Because ultrasound penetrates well through soft tissues and can be focused on distant spots that measure mere millimetres, the energy absorption elevates tissue temperature with such sharp thermal gradients that the boundaries of the treated tissue are clearly demarcated, and there is no damage to the overlying or surrounding tissues. Similar, well-controlled, noninvasive deep focusing cannot be achieved by any other heating method.
This power is now clinically available in the U.S. after a magnetic resonance imaging-guided and monitored focused ultrasound system (ExAblate 2000 from InSightec, based in Haifa, Israel) was approved in 2004 by the Food and Drug Administration for the noninvasive surgery of uterine fibroids. This device was a product of the research of Dr. Kullervo Hynynen in his laboratory at Brigham and Women's Hospital and Harvard Medical School prior to his recruitment to Sunnybrook Research Institute in 2006.
Although diagnostic ultrasound-guided focused ultrasound devices are used for different tumours in China and Japan, and in Europe for prostate cancer, they are limited by the lack of monitoring of the induced thermal exposure. Traditional surgery is often combined with chemotherapy and/or radiation therapy to reduce the number of surviving cancer cells. Likewise, the effectiveness of ultrasound surgery could also be maximized by combining it with these other therapies. Our aim in this project is to develop novel treatments that will explore the ability to potentiate therapeutic effects through the use of ultrasound exposure with microbubbles or other agents that can be locally activated. Specific goals are as follows:
- to perform fundamental studies of targeted therapy with ultrasound
- to develop methods for targeted local molecular therapy
- to evaluate ultrasound-activated agents
- to develop targeted liver therapeutics.
