NanoKnife side effects
As a minimally-invasive treatment, the side effects of NanoKnife are much less than surgery.
Based on our one-year outcome audit of 265 patients, NanoKnife IRE (NICE IPG768) has minimal side effects compared with radical surgery: 97% of men maintained urinary continence and 90%+ preserved sexual function. Below we explain what to expect before, during, and after NanoKnife treatment, including recovery timelines and potential side effects.
Will I be in pain after focal therapy?
Urinary continence
97% maintained urinary continence after NanoKnife (FTC audit, n=265)
What to expect
NanoKnife targets only the cancerous tissue rather than the whole prostate, preserving the surrounding nerves and structures. In our clinic’s experience, this means the likelihood of long-lasting erectile dysfunction or incontinence is significantly lower than with radical prostatectomy — our audit data shows 97% continence and 90%+ sexual function preservation.
NanoKnife IRE is a minimally invasive outpatient procedure performed under general anaesthetic. Fine needles are placed through the perineum to deliver targeted electrical pulses to the tumour — the entry points are much smaller than incisions from laparoscopic prostatectomy. Side effects are usually mild and short-lived. They can include:
- Dysuria — pain or burning sensation when you urinate, typically resolving within 1-2 weeks
- Urinary tract infection — a small increased risk due to the needles and post-procedure catheter (antibiotics are given as a precaution)
- Blood in urine or semen — common in the days or weeks after treatment as treated cells break down; this is expected and not a cause for concern
- Decreased or absent ejaculatory fluid — a small risk that could affect fertility
- Erectile dysfunction — in our clinic’s experience, 90%+ of men preserve sexual function, especially if function was good before treatment
- Temporary urinary retention — managed with a catheter for 1-3 days post-procedure
NanoKnife recovery timeline
NanoKnife is performed as an outpatient procedure — you go home the same day. Based on our clinic’s experience treating over 2,000 patients with focal therapy, here is a typical recovery timeline:
| Timeframe | What to expect |
|---|---|
| Day of treatment | Procedure under general anaesthetic; home same day with a catheter |
| 1-3 days | Catheter removed; mild discomfort and bruising around needle entry sites |
| 1-2 weeks | Dysuria and blood in urine resolve; most men return to normal activities. Our patient data shows 85% return to work within two weeks |
| 2-4 weeks | Any temporary urinary symptoms settle; sexual function typically returns to baseline |
| 3 months | Follow-up MRI scan to assess treatment effectiveness |
| 12 months | Follow-up biopsy — in our audit of 265 patients, 90% were cancer-free at one year |
Every patient’s recovery is different. Your consultant will provide a personalised recovery plan during your consultation.
NanoKnife side effects vs radical prostatectomy
In our clinic’s experience, NanoKnife IRE (NICE IPG768) offers significantly fewer side effects than radical prostatectomy:
| Side effect | NanoKnife IRE (FTC audit, n=265) | Radical prostatectomy (published data) |
|---|---|---|
| Urinary incontinence | Less than 2% | 10-20% |
| Erectile dysfunction | Less than 10% (90%+ preserve function) | 30-70% |
| Hospital stay | Outpatient (same day) | 1-3 days |
| Catheter duration | 1-3 days | 1-2 weeks |
| Return to work | 85% within 2 weeks | 4-6 weeks |
| NICE approved | Yes (IPG768) | Yes |
Source: FTC outcome audit (n=265, October 2025) for NanoKnife data. Prostatectomy data from published literature.
For a full explanation of how NanoKnife works, visit our NanoKnife IRE treatment page.
“If you’re deemed suitable for [NanoKnife], it really is a no brainer. I think to go down this line first is the only way if you want to minimise your possible after effects.”
Brian Bishop
The Focal Therapy Clinic patient
Hear from some of our previous patients about their experience with NanoKnife.
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If you’ve got any questions about your prostate cancer diagnosis or want to know more about HIFU treatment or NanoKnife treatment, don’t hesitate to get in touch with our friendly, knowledgeable team.
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