Focal therapy using high-intensity focused ultrasound for localised prostate cancer

2.1 Prostate cancer can cause some lower urinary tract symptoms such as frequency, urgency, hesitancy, terminal dribbling and an overactive bladder. Localised prostate cancer is confined to the prostate and has not spread to nearby tissues or other parts of the body.

2.2 NICE's guideline on prostate cancer describes how to diagnose and manage prostate cancer. Decisions on treatment are based on imaging, tumour staging, risk assessment and prostate-specific antigen (PSA) levels. For some people, localised prostate cancer grows slowly or not at all, and treatment may not be necessary. In such cases, watchful waiting or active surveillance strategies may be appropriate. If treatment is needed, several options are available. These include radical treatments (such as radical prostatectomy, external beam radiotherapy and radical brachytherapy), focal treatments (such as focal high-intensity focused ultrasound [HIFU], focal cryoablation, irreversible electroporation, focal laser ablation and focal brachytherapy) and adjunctive treatments (such as chemotherapy and androgen deprivation therapy).

2.3 Imaging and biopsy mapping are used to confirm that the tumour is suitable for focal therapy and to show its precise location. With the person under spinal or general anaesthesia, the bladder is catheterised using a urethral or supra-pubic catheter and the HIFU probe is inserted transrectally. Ultrasound imaging guidance is used to position the probe and to monitor the procedure. Pulses of HIFU are directed at the targeted part of the prostate, inducing tumour necrosis by a thermal effect and causing cavitation (which can be visualised by ultrasound to assess the adequacy of treatment) until satisfactory ablation of the target area is judged to have occurred. This procedure differs from standard whole-gland HIFU in that only some of the prostate is treated. Transurethral resection of the prostate may be done at the same time as focal HIFU to reduce urinary symptoms.