The robotic HIFU probe is positioned into the rectum under anaesthesia. A crystal within the probe vibrates at a specific frequency when an electric current passes through it, and this produces ultrasound waves at 4 MHz
The ultrasound waves pass through body tissue and some of the waves are reflected back to the crystal producing a real time image of the prostate and its surrounding structures on a computer screen, which is monitored in by the Urologist.
At the same time, by increasing the intensity of the ultrasound waves and focusing the waves on a single point (like a magnifying lens), high energy is delivered to the prostate tissue. This will raise the temperature to 70-100°C and cause permanent tissue ablation (cell death) of the prostate cancer. Dead tissue then sloughs out and is passed with urine.
The prostate gland is carefully mapped out using computer software, to preserve vital structures including the external urinary sphincter, neurovascular bundles and rectum.
HIFU ablation can be tailored to the individual patient’s prostate cancer, utilising the results of Transperineal Prostate Biopsy, Multiparametric MRI scans and PSMA PET scans.
Men with prostate cancer involving several areas of the prostate are treated with Whole of Prostate Ablation.
However, men with cancer in a localised area of the prostate, can be treated with Partial Prostate Ablation. This is sometimes referred to as Focal Prostate Ablation. Partial Prostate Ablation has important advantages for preservation of sexual function including erections. (Ahmed et al)