To determine the adverse events and genito-urinary side-effect profile of focal therapy to treat localised low to intermediate risk prostate cancer using irreversible electroporation (Nanoknife™).

Inclusion Criteria:

• Histologically proven prostate cancer, Gleason Score </=7
• An anterior visible lesion on mpMRI, that is accessible to IRE treatment
• Transperineal prostate biopsies (template mapping and/or limited targeted) correlating with clinically significant lesion in the area of the MR-visible lesion (within 2 Barzell zones)
• Absence of clinically significant disease outside of the planned treatment zone, from histopathology and/or mpMRI findings
• Stage radiologicalT1-T2cN0M0 disease, as determined by local guidelines
• Serum PSA </=15 ng/ml
• Life expectancy of >/= 10 years
• Signed informed consent by patient
• An understanding of the English language sufficient to understand written and verbal information about the trial and consent process

Exclusion Criteria:

• Men who have had previous radiation therapy
• Men who have had androgen suppression/hormone treatment within the previous 12 months for their prostate cancer
• Men with evidence of metastatic disease or nodal disease outside the prostate on bone scan or cross-sectional imaging
• Men with a non-visible tumour on mpMRI
• Men with an inability to tolerate a transrectal ultrasound
• Men with latex allergies
• Men who have undergone prior significant rectal surgery preventing insertion of the TRUS probe (decided on the type of surgery in individual cases)
• Men who have had previous IRE, HIFU, cryosurgery, thermal or microwave therapy to the prostate.
• Men who have undergone a Transurethral Resection of the Prostate (TURP) for symptomatic lower urinary tract symptoms within 6 months. These patients may be included within the trial if deferred from consenting and screening until at least 6 months following the TURP.
• Men not fit for major surgery as assessed by a Consultant Anaesthetist
• Men unable to have pelvic MRI scanning (severe claustrophobia, permanent cardiac pacemaker, metallic implant etc likely to contribute significant artefact to images)
• Presence of metal implants/stents in the urethra
• Men with renal impairment with a GFR of <35ml/min (unable to tolerate Gadolinium dynamic contrast enhanced MRI).