Autumn 2004 Edition

HIFU ultrasonic beam trials for prostate cancer

High Intensity focused ultrasound treatment for prostate cancer was the subject of wide press coverage in November. Hailed as a revolutionary new technique, it has in fact been around for some time. Trials have been under way in Germany and France for over seven years. But what is new is the ability to provide more accurate targeting of the sound beams. As with all forms of radiotherapy it is the precision with which it can now be used that is making this technique a more realistic proposition. HIFU uses high energy ultrasound generated from a probe inserted in the rectum under a local anaesthetic. The sound waves are focused into an area of the prostate the size of a rice grain. First, the probe scans the the prostate and displays a three dimensional image of the gland on a computer screen. The surgeon then draws on the screen to tell the computer which areas of the prostate to destroy and which nerves to avoid. The probe heats up each piece of tissue to 90C in just one second, melting fat within the cells and causing them to die. In many ways the technique is very similar to cryosurgery which utilises the same concept of killing diseased cells but by a freezing process rather than one using heat. It seems likely that HIFU will be available at The Royal Surrey once trials are completed.