ABSTRACT
The percutaneous transperineal placement of small metal probes into the prostate under transrectal ultrasound guidance represents the most flexible therapeutic method for the destruction of prostatic cancer. Since the initial description of an animal model for ultrasound-guided cryoablation in 1991 this technique was designed to eradicate clinically localized prostate cancer through the destruction of the entire prostate.1 Treatment approaches, which now include computer-guided treatment-planning software, focused on the placement of 5-8 cryoprobes in an array that would result in the entire prostate gland becoming engulfed in lethal ice. This lethal ice, with a temperature below 20 to 40C, would injure and ultimately ablate prostatic tissue through a combination of direct cellular injury and vascular occlusion. The challenge of such an approach is to limit the destructive effects of the treatment to the prostate while sparing tissue such as the urethra, rectum, and neurovascular bundles. As always, the clinical challenge is to balance treatment efficacy against associated treatment-related toxicity.
