The NanoKnife is used in focal therapy of prostate cancer. The procedure is called irreversible electroporation (IRE). The cancerous tissue of the prostate is treated with high-voltage current. Healthy tissue is spared and side effects are thus reduced. IRE is suitable for patients qualifying for focal therapy. It also is a potential alternative for patients who do not want an operation or radiotherapy or who are, for reasons of health, unsuitable for such treatments.