Irreversible electroporation for treating prostate cancer

The condition

2.1 Prostate cancer is the most common cancer in men in the UK, with 50% of diagnoses in people aged 70 years and over. Most prostate cancers are either localised or locally advanced at diagnosis. Localised prostate cancer does not usually cause any symptoms, but some people might have some urinary problems or erectile dysfunction. Some people may not identify as men but may have a prostate.

Current treatments

2.2 Current treatments for localised prostate cancer include active surveillance, radical prostatectomy, external beam radiotherapy, brachytherapy, and ablation of the whole gland using cryotherapy or high-intensity focused ultrasound (as recommended in NICE's clinical guideline on prostate cancer: diagnosis and management). Hormone therapy (androgen deprivation or anti-androgens) is usually the primary treatment for metastatic prostate cancer, but is increasingly being used for locally advanced, non-metastatic disease.

The procedure

2.3 The aim of irreversible electroporation is to destroy cancerous cells by subjecting them to a series of short electrical pulses using high-voltage direct current. This creates multiple holes in the cell membrane, irreversibly damaging the cell's homeostatic mechanisms and leading to cell death.

2.4 The procedure is done with the person under general anaesthesia. A neuromuscular blocking agent is essential to prevent uncontrolled severe muscle contractions caused by the electric current. A number of electrode needles (typically 3 to 5) are introduced transperineally and inserted into, and adjacent to, the tumour in the prostate using image guidance. A series of very short electrical pulses is delivered over several minutes to ablate the tumour. The electrodes may then be repositioned to extend the zone of electroporation until the entire tumour and an appropriate margin have been ablated. Cardiac synchronisation is used to time delivery of the electrical pulse within the refractory period of the heart cycle, to minimise the risk of arrhythmia.