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NanoKnife to Treat Prostate Cancer

Evidence Review created on 09/23/2026 using AI4L / Opus 5.5

Also known as: Irreversible Electroporation, IRE, NanoKnife System, Nanoknife, Focal Irreversible Electroporation, Non-Thermal Irreversible Electroporation, Prostate IRE

Motivation

NanoKnife is a medical device that destroys a small, targeted area of cancer inside the prostate by passing brief, powerful electrical pulses between thin needles placed through the skin behind the scrotum. The pulses open tiny holes in the walls of cells so that they die, without the heat or freezing used by other methods. Its appeal is the prospect of treating only the tumor while sparing the nerves and muscles that control erections and bladder control.

Surgery and radiation that treat the whole gland control cancer well but often leave lasting problems with bladder control and sexual function. Treating only the diseased part of the gland, known as focal therapy, has grown as scans and targeted biopsies have improved. United States regulators recently cleared the device for destroying prostate tissue after a trial funded by its maker, and debate continues over how durable its cancer control is.

This review examines how well this approach controls prostate cancer, what side effects it carries, who appears best suited, and how results are tracked, for men weighing it against surgery, radiation, or careful watching.

Benefits - Risks - Protocol - Conclusion

This section lists expert overviews, commentaries and narrative reviews that discuss NanoKnife and focal treatment of prostate cancer in depth.

No directly relevant content was found from Rhonda Patrick, Peter Attia, Andrew Huberman, Chris Kresser, Life Extension or Lifespan.io; these platforms cover prostate cancer screening, surgery, freezing-based ablation or lifestyle, but not NanoKnife or electroporation in depth. Only four items are listed because few expert overviews or commentaries discuss this procedure in depth.

Grokipedia

  • Nanoknife

    An encyclopedic overview of the NanoKnife system’s technology and procedure, its uses in prostate, pancreatic and liver tumors, and its stated advantages and limitations.

Examine

No Examine article on NanoKnife or irreversible electroporation exists. Examine.com covers supplements and nutrition and does not typically cover medical devices or surgical procedures.

ConsumerLab

No ConsumerLab article on NanoKnife or irreversible electroporation exists. ConsumerLab tests supplements and consumer health products and does not typically cover medical devices or surgical procedures.

Systematic Reviews

This section lists systematic reviews and meta-analyses on irreversible electroporation for prostate cancer, covering cancer control, function and salvage use (treatment after a prior therapy has failed).

Mechanism of Action

NanoKnife delivers irreversible electroporation: trains of very short (about 70–100 microsecond), high-voltage direct-current pulses passed between two to six needle electrodes placed through the perineum (the skin between scrotum and anus) around the tumor. The electric field opens nanometer-scale pores in cell membranes. Above a threshold field strength the pores do not reseal, the cell loses control of its internal chemistry, and it dies over hours to days, largely through apoptosis (programmed cell death).

Because killing depends on field strength rather than heat, the extracellular matrix (the collagen scaffold between cells) is largely preserved. Proponents argue that this lets the urethra, blood vessels and nerve bundles serving continence and erections survive even when they lie next to the ablation zone.

Competing observations temper this view. High currents cause measurable resistive heating near the electrodes, so the method is not purely non-thermal. The edge of the zone contains cells that are only reversibly electroporated and can survive, one explanation for in-field residual cancer. Ablation shape also depends on electrode spacing and tissue conductivity, making coverage less predictable than planning suggests. Early human data (Geboers et al., 2025) suggest that ablated tumor releases antigens that activate cancer-specific T cells (immune cells that recognize tumor), with unproven clinical relevance.

As a device, NanoKnife has no half-life, receptor selectivity, tissue distribution or metabolism; its “dose” is set by voltage, pulse number, pulse length and electrode geometry.

Historical Context & Evolution

Electroporation, the use of electric pulses to open cell membranes, was developed from the 1970s as a reversible laboratory technique for moving genes and drugs into cells. In 2005 bioengineers Rafael Davalos, Lluis Mir and Boris Rubinsky proposed using irreversible pulses to kill tissue without heat. AngioDynamics commercialized the approach as NanoKnife, originally cleared in the United States in the late 2000s for general surgical ablation of soft tissue and used first in liver and pancreatic tumors.

Prostate use followed the rise of focal therapy, driven by better MRI, targeted biopsy and the burden of incontinence and erectile dysfunction after whole-gland treatment. The first prostate cases were reported in 2010, according to an editorial commentary; University College London’s NEAT trial confirmed feasibility, and St Vincent’s in Sydney built the largest long-term cohort from 2013. German private clinics applied it across all risk groups, including whole-gland ablation.

The 17-center PRESERVE trial, funded by the manufacturer AngioDynamics, led to U.S. Food and Drug Administration (FDA) 510(k) clearance (a pathway based on similarity to existing devices) for prostate tissue ablation in December 2024. That clearance covers tissue ablation, not a claim of cancer cure. Early enthusiasm has been tempered by out-of-field recurrences, while functional results have stayed consistent. The AUA/ASTRO guideline (American Urological Association/American Society for Radiation Oncology) calls focal ablation investigational, and the EAU guideline limits it to trials or registries; both panels’ urologist and radiation-oncologist members earn revenue from radical treatments and from focal procedures.

Expected Benefits

High 🟩 🟩 🟩

Ablation of the Targeted Tumor

Focal IRE destroys the biopsy-proven, MRI-visible index lesion (the dominant tumor) in most treated men, confirmed by biopsy of the treated zone. Evidence comes from prospective single-arm trials, including the AngioDynamics-funded PRESERVE trial and the independent NEAT trial, plus cohorts; no randomized comparison with surgery or radiation exists. In-field control improves past the learning curve. For cancer recurring after radiotherapy, salvage IRE controlled local disease in about three-quarters of men in one trial and one cohort (systematic review), though metastases still appeared in some.

Magnitude: Negative in-field biopsy at 12 months in 71% (any cancer) and 84% (clinically significant cancer) of 121 PRESERVE patients; pooled in-field clinically significant cancer 8.9% across 49 focal therapy cohorts in a meta-analysis; after radiation failure, local control 78% in the 37-man FIRE trial (Blazevski et al., 2023) and 77% in a 74-man cohort (Geboers et al., 2023).

Urinary Continence and Urinary Symptoms Preserved

Because the sphincter and most of the gland are spared, nearly all men remain pad-free, and urinary symptom scores are stable or improve. This holds across prospective trials and cohorts. A propensity-matched comparison (patients paired on similar characteristics) with robot-assisted radical prostatectomy found better pad-free continence after IRE at every timepoint to 12 months. Losses are larger after salvage treatment of radiation-recurrent cancer.

Magnitude: Pad-free rates 96.7–100% after primary IRE across 19 studies (Zhang et al., 2025); absolute continence advantage over robotic prostatectomy of 13–14 percentage points at 6–12 months (Scheltema et al., 2018).

Erectile Function Largely Preserved

Most men with good baseline erections keep erections sufficient for intercourse, although scores dip in the first months and a minority lose function (see Risks). Multiple prospective series report this, and a matched comparison with robotic prostatectomy found a sizable advantage for IRE at 12 months. Comparative data remain non-randomized and come largely from centers that perform the procedure.

Magnitude: 84% of PRESERVE men with good baseline function kept erections sufficient for penetration at 12 months (George et al., 2026); absolute advantage over robotic prostatectomy of 22 percentage points at 12 months (Scheltema et al., 2018).

Medium 🟩 🟩

Avoidance of Radical Treatment for Years ⚠️ Conflicted

In the largest long-term cohort (229 Sydney men), most men avoided surgery, radiation or hormone therapy for years after focal IRE, with survival free of spread near 100%. This is one center’s uncontrolled experience from surgeons who developed the procedure. A German private-clinic series by founders offering IRE claimed prostatectomy-like durability, but a matched cohort and a US database found more failure after ablation; the series lacked a comparison group and defined failure differently. On balance, most men defer radical treatment for years, but failure exceeds that after surgery.

Magnitude: Failure-free survival (no radical treatment, nodal or distant disease) 91% at 3 years, 84% at 5 years and 69% at 8 years; 17% progressed to radical treatment (Scheltema et al., 2023); 5-year failure-free survival 73.4% after any gland ablation versus 86.9% after prostatectomy (Velasquez et al., 2026).

Low 🟩

Later Surgery Remains Feasible

If cancer returns after IRE, robotic radical prostatectomy remains technically feasible with continence largely preserved. Evidence is one retrospective multicenter series of 39 men; nearly half had locally advanced disease at surgery.

Magnitude: Continence 94.4% and erectile function 52.9% after salvage prostatectomy, with positive surgical margins (cancer at the cut edge) in 25.6% (van Riel et al., 2022).

Speculative 🟨

Systemic Anti-Tumor Immune Activation

In 20 men, IRE depleted regulatory T cells (immune cells that dampen responses) and expanded cancer-specific T cells, unlike prostatectomy (Geboers et al., 2025). Basis is immune biomarkers only; no outcome data.

Benefit-Modifying Factors

  • Genetic polymorphisms: Germline BRCA2 and ATM variants (DNA-repair genes) and HOXB13 (a prostate-development gene) raise the risk of aggressive, multifocal (several separate tumors) cancer, reducing the chance that treating one lesion suffices; no IRE-specific outcome data exist.
  • Baseline biomarkers: An EAU review by ablation urologists sets PSA density (PSA divided by prostate volume) below 0.15–0.20 ng/mL/cm³ as ideal; a 171-man series found neither it nor PSMA (prostate-specific membrane antigen) scan uptake predicted failure, possibly reflecting pre-selected patients and limited follow-up biopsy.
  • Tumor grade: Benefit is greatest for grade group 2–3 disease; recurrence rises steeply for Gleason 8–10 tumors, and grade group 1 disease usually suits active surveillance (monitoring without treatment) instead.
  • Lesion size and location: Targets of about 20 mm or less are reliably covered; anterior and apical lesions, which are hard to reach with ultrasound-based energies, suit transperineal IRE; hemi-gland templates improve control for larger lesions.
  • Sex: Prostate treatment applies only to men, so no sex-based differences in benefit exist.
  • Pre-existing conditions: Prior radiotherapy lowers local control compared with primary treatment; prior transurethral resection of the prostate (TURP) or a very large gland complicates electrode placement and coverage.
  • Age: Men with under 10 years’ life expectancy gain little from any local treatment; younger men gain most function-years but face decades of possible new cancer in the untreated gland.

Potential Risks & Side Effects

High 🟥 🟥 🟥

Cancer Persisting or Arising Elsewhere in the Gland

Focal treatment leaves most of the prostate untreated, and prostate cancer is often multifocal. Clinically significant cancer is found outside, and less often inside, the ablation zone in a substantial minority, driving retreatment or radical treatment. An independent commentary argues PRESERVE’s early failure rate is too high and will rise with time; some failures reflect disease missed before treatment rather than true recurrence.

Magnitude: Clinically significant cancer anywhere in 26% of PRESERVE patients at 12 months, 18% outside the treated zone (editorial commentary); residual clinically significant cancer in 24% on follow-up biopsy over a median 5 years (Scheltema et al., 2023).

Decline in Erectile Function

Erectile function typically dips in the first months and then partly recovers, but a minority of men lose erections sufficient for intercourse. Evidence comes from prospective trials, long-term cohorts and a systematic review using validated erectile-function questionnaires. The likely mechanism is injury to nerve bundles beside ablations at the back and sides of the gland plus post-ablation inflammation. Losses are greater after salvage IRE in irradiated glands and after larger hemi-gland ablations.

Magnitude: Erections sufficient for intercourse fell from 71% to 58% at a median of 5 years (Scheltema et al., 2023); declines of 3–22 percentage points across 10 studies (Cheng et al., 2025); after salvage IRE, 35% fell to 15% (Blazevski et al., 2023).

Short-Term Urinary Symptoms, Hematuria and Hematospermia

Needle trauma and post-ablation swelling commonly cause frequency, urgency, painful urination and hematuria (blood in urine) for days to weeks, sometimes with urinary retention (inability to empty the bladder) needing a catheter. Hematospermia (blood in semen) is also among the commonest complications in a systematic review of 29 studies. Trials grade most of these events 1–2 on the Common Terminology Criteria for Adverse Events (CTCAE; grade 1–2 means mild to moderate).

Magnitude: Adverse events in 86% of PRESERVE patients, predominantly low-grade (editorial commentary); self-limiting urgency, frequency or hematuria in 19% of FIRE trial patients (Blazevski et al., 2023).

Urinary Tract Infection and Epididymitis

Transperineal needles and catheters can introduce bacteria, causing urinary tract infection (UTI) or epididymitis (inflammation of the sperm-carrying tube behind the testicle). UTI is among the most frequently reported complications in systematic reviews, and most cases resolve with antibiotics.

Magnitude: Among 25 men, grade 3 complications were one epididymitis and one UTI (Murray et al., 2016); UTI and hematuria were the commonest complications across 1,452 patients (Zhang et al., 2025).

Urinary Incontinence

New incontinence is rare after primary focal IRE but more frequent after salvage IRE in irradiated glands, where tissue heals poorly. The mechanism is ablation reaching the external urinary sphincter near the prostate apex. Evidence comes from prospective cohorts and systematic reviews of primary and salvage IRE.

Magnitude: Pad-free rates fell by 1–2 percentage points in primary series and by 4–33 points in salvage series (Cheng et al., 2025); continence 73–100% after salvage IRE (Yilmaz et al., 2025).

Medium 🟥 🟥

Urethral Sloughing and Stricture

Dead tissue from ablations abutting the urethra can shed into it (sloughing), causing blockage that may need transurethral resection (endoscopic removal through the urethra). It is most frequent after salvage IRE of irradiated glands, and urethral strictures (scar narrowing) also occur. Evidence comes from one prospective salvage trial and cohort data.

Magnitude: Grade 3 urethral sloughing needing resection in 19% (7 of 37) in the FIRE salvage trial (Blazevski et al., 2023) and 11% (8 of 74) in a salvage cohort (Geboers et al., 2023).

Residual Cancer Missed on Follow-Up MRI

Post-ablation inflammation and scarring make MRI unreliable for spotting leftover cancer, so relying on imaging alone can delay detection of failure. A multicenter validation study found MRI missed most biopsy-positive locations, so follow-up biopsy remains necessary.

Magnitude: MRI sensitivity (share of cancers detected) 43.6% and negative predictive value (chance a negative scan is truly negative) 86.7%; 38 of 57 positive biopsy locations missed (Geboers et al., 2022).

Rectourethral Fistula

A rectourethral fistula (abnormal channel between rectum and urethra) is rare but serious, needing prolonged catheter drainage or surgery. It occurred once in the PRESERVE trial, according to an editorial commentary that notes only two other published cases, and it is the most often reported prostate event in FDA device-event reports.

Magnitude: Two cases across 29 studies (Cheng et al., 2025); fistula was the commonest prostate event in FDA MAUDE (Manufacturer and User Facility Device Experience) reports, with rising case numbers (Xiang et al., 2025).

Low 🟥

Cardiac Arrhythmia

Electrical pulses can trigger irregular heartbeats if delivered during the heart’s vulnerable phase, so pulses are synchronized to the electrocardiogram (ECG). Arrhythmias appear in liver IRE device reports; the prostate lies far from the heart.

Magnitude: Not quantified in available studies. Prostate trials report no arrhythmia rates, and data come only from liver-ablation device reports (Xiang et al., 2025).

Speculative 🟨

Tumor Seeding Along Needle Tracks

Electrodes passing through tumor could theoretically carry cancer cells into the needle track. No prostate IRE cases are reported; the concern is mechanistic, extrapolated from other needle-based cancer procedures.

Risk-Modifying Factors

  • Genetic polymorphisms: Germline BRCA2, ATM or HOXB13 variants predispose to multifocal, aggressive cancer, raising the risk of out-of-field failure after partial treatment.
  • Baseline biomarkers: Higher PSA density and PSMA (prostate-specific membrane antigen) PET (positron emission tomography) uptake outside the target flag hidden disease; low platelets or high INR (international normalized ratio, a clotting measure) raise bleeding risk.
  • Sex: Only men undergo prostate IRE, so no sex-based risk differences exist.
  • Prior radiotherapy: Irradiated tissue heals poorly, raising rates of incontinence, urethral sloughing, erectile loss and fistula compared with primary treatment.
  • Pre-existing conditions: Prior rectal surgery or inflammatory bowel disease raises fistula risk; pacemakers, defibrillators or arrhythmias raise cardiac risk; bleeding disorders raise hematuria; prior TURP raises sloughing risk.
  • Age: Older men carry higher general-anesthesia risk and often lower baseline erectile function; younger men face longer exposure to new cancer in untreated tissue.

Key Interactions & Contraindications

  • Anticoagulants (blood thinners: warfarin, apixaban, rivaroxaban, dabigatran): Caution; multiple needle punctures raise bleeding and hematuria. Usually paused 2–5 days before, depending on agent and kidney function, with bridging (temporary injectable anticoagulant cover) only for high clotting risk.
  • Antiplatelet drugs (clot-preventing agents: clopidogrel, ticagrelor, prasugrel): Caution; increased bleeding. Typically stopped 5–7 days before when cardiac risk allows; never stopped after a recent coronary stent without cardiology input.
  • 5-alpha-reductase inhibitors (prostate-shrinking drugs: finasteride, dutasteride): Monitor; they roughly halve PSA, masking a rise after IRE. Stable dosing, with PSA read against the on-drug baseline or doubled, keeps trends interpretable.
  • Androgen deprivation therapy (testosterone-lowering hormone treatment: leuprolide, degarelix, relugolix): Monitor; suppresses PSA and shrinks tumor, confounding assessment of ablation success. Starting it around treatment is generally limited to defined protocols.
  • Testosterone therapy (testosterone cypionate, gels): Caution; may stimulate residual cancer and raises PSA. Continued use generally involves urologist review and close PSA tracking.
  • Alpha-blockers (prostate-relaxing drugs: tamsulosin, alfuzosin): Monitor; ease post-procedure urinary retention but cause dizziness on standing. Often started or continued for 2–4 weeks after ablation.
  • PDE5 inhibitors (erection drugs that widen penile blood vessels: sildenafil, tadalafil): Monitor (beneficial); additive benefit for erectile recovery after ablation. Absolute contraindication with nitrates (chest-pain drugs that widen blood vessels: nitroglycerin, isosorbide mononitrate) because of severe low blood pressure.
  • Neuromuscular blocking agents (muscle-paralyzing anesthesia drugs: rocuronium, vecuronium): Required; incomplete muscle paralysis lets pulses trigger violent contractions that displace electrodes. Anesthesia teams confirm full blockade before pulsing.
  • Implanted cardiac devices (pacemakers, implantable defibrillators): Caution; pulses may interfere with device sensing and cause arrhythmia. Cardiology review, device reprogramming and ECG-synchronized pulsing are standard.
  • NSAIDs (non-steroidal anti-inflammatory pain relievers: aspirin, ibuprofen, naproxen): Caution; increased bleeding. Commonly stopped 5–7 days before; low-dose aspirin continued or stopped per prescriber.
  • Supplements with antiplatelet effects (fish oil, vitamin E, Ginkgo biloba, garlic, turmeric): Caution; additive bleeding risk with other agents. Usually stopped 7 days before the procedure.
  • Saw palmetto (Serenoa repens): Monitor; may slightly alter urinary symptoms and PSA readings. Stable use across follow-up keeps PSA trends interpretable.
  • Prior pelvic radiotherapy: Caution; greater tissue injury, sloughing and fistula risk. Salvage IRE is performed only at experienced centers with modified margins and close follow-up.

Populations who should avoid NanoKnife:

  • Men with metastatic disease (lymph node or distant spread on PSMA PET or conventional staging)
  • Men with high-risk cancer (grade group 4–5, PSA above 20 ng/mL or stage T3 or higher, meaning tumor extending beyond the prostate) outside a clinical trial
  • Men with multifocal clinically significant cancer in both lobes that no focal or hemi-gland template can cover
  • Men with low-volume grade group 1 cancer, for whom active surveillance is generally preferred
  • Men unfit for general anesthesia (American Society of Anesthesiologists physical status IV or higher)
  • Men with active untreated UTI or uncorrectable bleeding disorders (INR above 1.5 or platelets below 50 × 10⁹/L)
  • Men with unstable cardiac arrhythmia or a heart attack (myocardial infarction) within the past 3 months
  • Men with a life expectancy under 10 years

Risk Mitigation Strategies

  • Rigorous patient selection: High-quality MRI plus transperineal targeted and systematic biopsy, with PSMA PET where available, reduces missed out-of-field disease, the leading cause of failure.
  • Adequate safety margins: Margins of 5–10 mm around the MRI lesion, or a hemi-gland template for larger lesions, reduce in-field persistence at some cost to erectile function.
  • Experienced high-volume center: Outcomes improve after the learning curve; choosing centers with dozens of prior cases and registry participation reduces in-field failure and complications.
  • ECG-synchronized pulsing and full paralysis: Delivering pulses in the heart’s refractory period (the brief phase when it cannot be re-triggered) under complete neuromuscular blockade prevents arrhythmia and electrode displacement.
  • Rectal protection: Keeping electrodes at least 5 mm from the rectal wall, with saline hydrodissection (fluid injected to push the rectum away) or a rectal spacer for posterior lesions, reduces fistula risk.
  • Infection prophylaxis: A single perioperative antibiotic dose and a negative urine culture beforehand reduce UTI and epididymitis.
  • Catheter drainage: A urethral catheter for 3–7 days, longer after salvage IRE, prevents retention; early transurethral resection manages sloughing.
  • Scheduled biopsy at 12 months: Biopsy regardless of MRI findings catches residual cancer that imaging misses, allowing timely retreatment.
  • Penile rehabilitation: Daily low-dose tadalafil (2.5–5 mg) for 3–6 months, where appropriate, supports recovery of erectile function.
  • Antithrombotic plan: A documented plan for pausing and restarting anticoagulants and antiplatelets reduces bleeding without raising clotting risk.

Therapeutic Protocol

  • Standard procedure: Under general anesthesia, 2–6 needle electrodes are placed transperineally with TRUS (transrectal ultrasound) guidance and MRI fusion, spaced 10–20 mm apart, with about 90 pulses of 70–90 microseconds at roughly 1,500 V/cm per electrode pair.
  • ECG synchronization: Pulses are timed to the heart’s refractory phase, and deep neuromuscular blockade prevents muscle contraction during each train.
  • Ablation extent: Focal (lesion plus margin), hemi-gland (one side) or extended templates; an EAU review by urologists who perform ablation reports better cancer control with hemi-gland and better erectile preservation with focal ablation.
  • Procedure and recovery: Takes 1–2 hours, often as a day case or overnight stay; a catheter stays 3–7 days, and most men resume normal activity within 1–2 weeks.
  • Alternative focal energies: High-intensity focused ultrasound (HIFU), cryotherapy, focal laser ablation and transurethral ultrasound ablation (TULSA) are competing partial-gland options with similar pooled outcomes; lesion location often guides choice.
  • Whole-gland treatment and surveillance: Radical prostatectomy, external-beam radiotherapy or brachytherapy (radioactive seeds placed in the prostate), and active surveillance remain parallel options for the same patients, each with its own balance of cancer control and side effects.
  • Pioneers and proponents: Phillip Stricker (St Vincent’s, Sydney), Mark Emberton and Massimo Valerio (University College London, NEAT), Michael Stehling (Vitus Prostate Center, Offenbach), Jonathan Coleman (Memorial Sloan Kettering) and Arvin George (PRESERVE lead).
  • Combination with radiotherapy: An experimental approach pairs IRE with reduced-dose radiotherapy (32.5 Gy, where gray is the radiation dose unit, in five fractions); a 10-man phase 1 study found no residual cancer at 12 months.
  • Time of day: An elective procedure scheduled around anesthesia logistics; no evidence suggests time of day affects outcomes.
  • Half-life: Not applicable; the device leaves no drug in the body. The ablation is permanent, and PSA reaches its lowest point at a median of 3.5 months.
  • Single versus repeated sessions: Delivered as a single session; repeat IRE is feasible for in-field recurrence, as in 12 of 123 men in a Sydney cohort.
  • Genetic polymorphisms: Germline testing for BRCA2, ATM and HOXB13 before choosing a focal approach; carriers are generally counseled toward whole-gland treatment or surveillance because of multifocal risk.
  • Sex: Applies only to men; no sex-based dosing or response differences exist.
  • Age: Men in their 50s to 70s with over 10 years’ life expectancy are typical candidates; older men need anesthesia fitness assessment.
  • Baseline biomarkers: PSA density below about 0.15–0.20 ng/mL/cm³, a single PI-RADS (Prostate Imaging Reporting and Data System) 4–5 lesion, and no extra PSMA-avid foci favor focal treatment.
  • Pre-existing conditions: Prior radiotherapy calls for salvage-specific protocols and longer catheterization; prior TURP, rectal disease or cardiac devices require tailored electrode placement or specialist input.

Discontinuation & Cycling

  • One-time procedure, lifelong surveillance: IRE is a short-term intervention delivered once, but the untreated gland requires surveillance for life.
  • Withdrawal effects: None; no drug is involved and nothing is stopped.
  • Tapering: Not applicable to a single ablation.
  • Cycling: Not applicable; repeat ablation is used only for documented residual or new cancer, not on a schedule.
  • Catheter removal: The catheter is removed after 3–7 days, or later after salvage treatment, once swelling settles.
  • Switching to radical treatment: Prostatectomy or radiotherapy remain available after IRE failure, although surgery can be technically harder.

Sourcing and Quality

  • Single-manufacturer device: The NanoKnife System (AngioDynamics, Latham, New York) holds FDA 510(k) clearance for prostate tissue ablation and CE marking (European conformity) in Europe.
  • Look-alike technologies: High-frequency IRE (H-FIRE), Chinese steep-pulse devices and electrochemotherapy (reversible pulses that let chemotherapy enter cells) use related principles but are distinct devices with separate, smaller evidence bases.
  • Center experience: Most PRESERVE sites (14 of 17) performed their first cases during the trial, per an editorial commentary; results improve with experience, so case volume, published outcomes and registry participation are key quality markers.
  • Established programs: Long-running programs include St Vincent’s (Sydney), Wesley Hospital (Brisbane), University College London, Charité (Berlin), Memorial Sloan Kettering, Weill Cornell and NYU Langone (New York).
  • Diagnostic quality: Outcomes depend on accurate targeting; MRI reported by experienced prostate radiologists, transperineal template plus targeted biopsy and PSMA PET are markers of a rigorous pathway.
  • Device safety reporting: Supplement-style third-party testing does not apply; device problems are tracked through the FDA MAUDE database, where malfunctions have declined in recent years.

Practical Considerations

  • Time to effect: Tissue death is immediate; PSA reaches its lowest point at a median of 3.5 months, and the 12-month biopsy confirms whether the tumor was destroyed.
  • Common pitfalls: Treating MRI-invisible or multifocal disease, skipping the 12-month biopsy, relying on PSA alone (no validated failure threshold exists after focal therapy), and treating grade group 1 cancer suited to surveillance.
  • Regulatory status: FDA clearance covers “prostate tissue ablation”, not a cancer-treatment claim; AUA/ASTRO calls focal ablation investigational and EAU restricts it to trials or registries, and both panels’ members earn revenue from radical and focal treatments.
  • Cost and access: Many insurers and health systems do not routinely reimburse focal IRE, so it is often self-funded, with costs commonly in the tens of thousands of US dollars; few centers offer it.
  • Payer incentives: A Dutch trial registration estimates €5,456 per patient in avoidable side-effect costs, yet non-reimbursement limits trials and uptake; payers’ mixed incentives are a potential structural bias in guideline and research funding.
  • Recovery and logistics: Travel to a specialist center, general anesthesia, 3–7 days of catheterization and repeated biopsies over follow-up are practical burdens.

Interaction with Foundational Habits

  • Sleep: Indirect. Catheterization and post-procedure urgency or night-time urination disrupt sleep for 1–2 weeks; the pulses have no known effect on sleep physiology. Limiting evening fluids and prescribed alpha-blockers help during recovery.
  • Nutrition: Indirect. Drinking about 2 liters of fluid daily reduces infection and clot retention after ablation, and fiber prevents straining. Long term, a Mediterranean-style, plant-forward diet supports cardiovascular health, which underpins erectile function.
  • Exercise: Indirect, potentiating functional recovery. Cycling, heavy lifting and high-impact training are typically paused for about 2 weeks because of perineal punctures and bleeding. Pelvic floor muscle training supports continence, and regular aerobic and resistance training helps preserve erectile function.
  • Stress management: Indirect. Focal treatment trades side effects for ongoing surveillance, and waiting for PSA results and biopsies can raise anxiety; no effect on cortisol is known. Clear follow-up schedules, survivorship support and mindfulness practices may ease this burden.

Monitoring Protocol & Defining Success

Baseline testing: Before treatment, candidates need a high-quality prostate MRI, a transperineal biopsy combining targeted cores from the lesion with systematic cores from the rest of the gland, and staging with PSMA PET where available, to confirm a single, organ-confined, grade group 2–3 tumor. Baseline PSA, PSA density, urine culture, platelets, INR, kidney function and an ECG support procedural safety, and validated urinary and sexual questionnaires set the functional reference point.

Ongoing monitoring: PSA at 3, 6, 9 and 12 months, then every 6 months to year 5 and annually thereafter; MRI at 6–12 months, then every 1–2 years or when PSA rises; transperineal biopsy of the treated zone and remaining gland at 12 months regardless of MRI findings; and questionnaires at 3, 6 and 12 months, then yearly.

Biomarker Optimal Functional Range Why Measure It? Context/Notes
PSA (total) Before: under 10 ng/mL for focal candidates. After: no established target; track nadir and trend against own baseline (a 60–70% fall by 6–12 months is typical) Response and relapse Conventional “normal” under 4 ng/mL does not apply after ablation; no validated PSA failure definition after focal therapy; ejaculation or cycling within 48 hours can raise PSA; results are most comparable from the same lab
PSA density Under 0.15 ng/mL/cm³ Flags hidden cancer PSA divided by MRI-measured prostate volume; 0.15 is also the conventional biopsy threshold
Prostate MRI score Before: single PI-RADS 4–5 lesion of 20 mm or less. After: PI-FAB 1 (no suspicious enhancement) Target and residual disease PI-FAB = Prostate Imaging after Focal Ablation score; MRI misses over half of residual cancer after IRE, so biopsy is still needed
Biopsy grade group Before: grade group 2–3 in the index lesion only. After 12 months: no grade group 2 or higher cancer Confirms ablation ISUP (International Society of Urological Pathology) grading; transperineal template plus targeted cores
PSMA PET/CT No uptake outside the prostate; single intraprostatic focus Excludes spread and extra lesions CT = computed tomography; complements MRI in selecting candidates
IIEF-5 score 22–25 Sexual function IIEF-5 = International Index of Erectile Function, 5-item version; conventional erectile dysfunction cutoff is 21 or less
IPSS 0–7 Urinary symptoms IPSS = International Prostate Symptom Score; conventional “mild” band is also 0–7
EPIC-26 incontinence domain Pad-free; score near 100 Continence EPIC-26 = Expanded Prostate Cancer Index Composite, 26-item version
Urine culture No growth Infection before ablation Any UTI is treated before the procedure
Platelets and INR Platelets 150–400 × 10⁹/L; INR 1.0–1.1 off anticoagulants Bleeding risk Conventional INR range 0.8–1.2; values are rechecked after anticoagulants are paused
eGFR 90 mL/min/1.73 m² or higher Contrast MRI and anesthesia safety eGFR = estimated glomerular filtration rate; conventional lower limit about 60; gadolinium contrast needs eGFR of at least 30
ECG Normal sinus rhythm Pulse synchronization and anesthesia Arrhythmia or implanted device requires cardiology review

Qualitative markers:

  • Urinary stream strength, urgency and any leakage during daily activities
  • Quality of erections, including morning erections, and ejaculatory volume
  • Return of energy and normal physical activity after recovery
  • Level of anxiety about recurrence and around PSA or biopsy results
  • Overall satisfaction with the treatment decision

Emerging Research

  • PRIS randomized trials (Sweden): NCT05513443 compares IRE with robot-assisted prostatectomy or radiotherapy in 184 men with intermediate-risk cancer; primary endpoints are continence and irritative urinary symptoms (protocol, Lantz et al., 2023).
  • ENFORCE randomized trial (Netherlands): NCT06223295 randomizes 356 men to focal therapy (HIFU, IRE or TULSA) or radical treatment, with non-inferior (no worse than a preset margin) cancer control at 36 months and quality of life at 12 months as co-primary endpoints (Te Molder et al., 2026).
  • PART randomized trial (United Kingdom): Partial ablation by HIFU or IRE versus radical treatment in 306 men, testing non-inferior cancer control at median 3 years; registered as ISRCTN17249875, with no NCT ID (Bryant et al., 2026).
  • WIRED trial (Canada): NCT06451445 treats 100 men with intermediate-risk cancer using NanoKnife, with negative in-field biopsy at 12 months and adverse events as primary endpoints; recruiting.
  • IRE plus radiotherapy: NCT05345444 (RTIRE, 48 enrolled, no longer recruiting) combines IRE with reduced-dose radiotherapy; phase 1 results in 10 men showed no residual cancer and no severe events (McClure et al., 2026).
  • Immune combinations: IRE induced cancer-specific T-cell responses (Geboers et al., 2025), prompting proposals to combine it with checkpoint inhibitors (drugs that release immune brakes) for higher-risk disease.
  • Signals that could weaken the case: Real-world data show lower 5-year failure-free survival after gland ablation than after surgery (Velasquez et al., 2026), and a small comparison found more biochemical recurrence (rising PSA) after IRE (Xia et al., 2026).
  • Better selection with PSMA PET: Commentators argue that routine PSMA PET before IRE could cut out-of-field failures that PRESERVE exposed (Cheng & Grummet, 2026).

Conclusion

NanoKnife destroys a targeted prostate tumor with brief electrical pulses instead of heat, cold, surgery or radiation. For men with a single, clearly visible tumor of moderate aggressiveness, the evidence consistently shows that the treated area is usually cleared, that bladder control is almost always kept, and that most men keep their erections. This matters most to men who value preserved function and accept close follow-up.

The main trade-off is durability. Because most of the gland is left untreated, a meaningful share of men later have significant cancer found elsewhere in the prostate or at the edge of the treated area, and some need repeat treatment or conventional surgery or radiation. Survival in the available studies looks excellent, but follow-up rarely exceeds several years, and the few comparisons with surgery point to more treatment failures after targeted tissue destruction. Scans alone miss much of any leftover cancer, so repeat biopsies are part of the package. Serious harms such as an abnormal channel between the bowel and the urinary tract are rare but real, and problems are more common when the method is used after failed radiation.

The evidence base is young and mostly lacks comparison groups. The largest trial was funded by the device maker, and much of the long-term data comes from centers that developed and offer the procedure. Professional bodies whose members earn income from surgery, radiation and these newer procedures alike still describe the approach as unproven against standard treatment.

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