Focal Therapy for Prostate Cancer: Cryotherapy, HIFU & More
- What is focal therapy?
- Who is a candidate for focal therapy?
- Cryotherapy (cryoablation) – freezing cancer cells
- HIFU (High-Intensity Focused Ultrasound)
- Focal laser ablation (FLA)
- Irreversible electroporation (IRE)
- Success rates – cancer control outcomes
- Side effects – lower than whole-gland treatment
- Focal vs. whole-gland treatment – comparison
- Interactive FAQ – 9 questions about focal therapy
What is focal therapy?
Focal therapy (also called partial gland ablation) is a treatment approach for prostate cancer that targets only the cancerous part of the prostate, leaving the rest of the gland untreated. This contrasts with whole-gland treatments (radical prostatectomy, whole-gland radiation, brachytherapy) that treat the entire prostate.
The goal of focal therapy is to destroy the visible cancer while preserving surrounding healthy tissue, thereby reducing side effects (erectile dysfunction, urinary incontinence).
Who is a candidate for focal therapy?
Ideal candidates for focal therapy meet the following criteria:
- Low-risk or favorable intermediate-risk prostate cancer: Gleason 6 or 3+4=7, low volume of pattern 4
- Unilateral (one side of the prostate): Cancer visible on MRI (PI-RADS 4-5) and confirmed on biopsy
- No evidence of spread: Negative MRI for extracapsular extension, no seminal vesicle invasion
- Prostate size <60 mL (preferred)
- Good baseline urinary and erectile function
- Patient preference to avoid whole-gland treatment side effects
Who is NOT a candidate?
- Multifocal cancer (cancer in both lobes) – whole-gland treatment needed
- High-risk cancer (Gleason 4+3=7, 8-10) – higher risk of progression
- Extracapsular extension (cancer outside prostate) – needs whole-gland treatment
- Large prostate (>80 mL) – technically challenging
Cryotherapy (cryoablation) – freezing cancer cells
Cryotherapy (cryoablation) uses extreme cold to freeze and destroy prostate cancer cells. It is the most established focal therapy modality.
How it works:
- Thin needles (cryoprobes) are inserted through the perineum into the prostate under ultrasound guidance
- Argon gas circulates through the probes, freezing tissue to -40°C
- A warming catheter protects the urethra
- A thermocouple monitors temperature near the neurovascular bundles
- Two freeze-thaw cycles are performed
Procedure details:
- Spinal or general anaesthesia
- Outpatient or 23-hour stay
- Catheter for 7-10 days
Success rates:
- 5-year biochemical recurrence-free survival: 70-85% (for appropriate candidates)
- In-field recurrence (cancer in treated area): 10-15%
- Out-of-field recurrence (cancer in untreated area): 10-20%
HIFU (High-Intensity Focused Ultrasound)
HIFU uses focused ultrasound waves to heat and destroy prostate cancer cells. It is the most commonly performed focal therapy worldwide.
How it works:
- A transrectal ultrasound probe emits focused ultrasound waves
- The waves are focused on a small target within the prostate
- Temperatures reach 80-100°C, causing coagulative necrosis
- Real-time ultrasound imaging guides treatment
Procedure details:
- Spinal or general anaesthesia
- Outpatient or 23-hour stay
- Catheter for 3-7 days
Success rates:
- 5-year biochemical recurrence-free survival: 75-85%
- In-field recurrence: 10-15%
- Out-of-field recurrence: 15-20%
Focal laser ablation (FLA)
Focal laser ablation uses laser energy delivered through thin optical fibres to destroy prostate cancer cells.
How it works:
- Laser fibres are inserted through the perineum into the prostate under MRI guidance
- Laser energy heats tissue to 60-80°C, causing coagulation
- MRI thermometry monitors temperature in real-time
Advantages:
- MRI guidance (most precise)
- Real-time temperature monitoring
- Very low side effect profile
Disadvantages:
- Limited long-term data
- Requires MRI-compatible equipment (specialised centre)
Irreversible electroporation (IRE)
IRE (also called Nanoknife) uses high-voltage electrical pulses to create pores in cancer cell membranes, leading to cell death without heat (non-thermal ablation).
How it works:
- Electrodes are inserted through the perineum into the prostate
- High-voltage electrical pulses (3,000 volts) are delivered
- Cell membranes are disrupted, causing apoptosis
- No thermal damage to surrounding structures (nerves, urethra)
Advantages:
- Preserves neurovascular bundles (better erectile function)
- Preserves urethra (lower incontinence risk)
- No heat sink effect (works near blood vessels)
Disadvantages:
- Requires general anaesthesia with paralytics (muscle relaxation)
- Limited long-term data
Success rates – cancer control outcomes
Success rates vary by modality and patient selection. Long-term data is limited compared to whole-gland treatments.
- 5-year biochemical recurrence-free survival: 70-85%
- Need for repeat treatment (any modality): 20-30% within 5 years
- Conversion to whole-gland treatment (surgery/radiation): 10-20% within 5 years
Important considerations:
- Focal therapy treats only visible cancer – microscopic cancer elsewhere may be missed
- Close follow-up with PSA, MRI, and repeat biopsy is essential
- If cancer recurs, whole-gland salvage treatment (surgery, radiation) is still possible
Side effects – lower than whole-gland treatment
Focal therapy has significantly lower rates of erectile dysfunction and urinary incontinence compared to whole-gland treatments:
Erectile dysfunction:
- Focal therapy: 10-20% at 1-2 years
- Whole-gland (surgery/radiation): 20-50%
Urinary incontinence:
- Focal therapy: <5% need pads (usually temporary)
- Whole-gland surgery: 5-10% need pads at 12 months
Other side effects:
- Urinary retention: 5-10% (temporary catheter)
- Hematuria (blood in urine): common, resolves in days
- Dysuria (painful urination): common, temporary
- Rectal injury: <1% (rare)
Focal vs. whole-gland treatment – comparison
Interactive FAQ – Focal therapy for prostate cancer
No – focal therapy has lower cancer control rates (70-85% 5-year recurrence-free) than whole-gland treatment (85-95%). However, it has fewer side effects.
Men with unilateral, low to favorable intermediate-risk prostate cancer (Gleason 6 or 3+4=7) visible on MRI, with good baseline urinary and erectile function.
No single "best" – cryotherapy has longest follow-up, HIFU is most common, IRE may have best erectile function preservation. Choice depends on centre expertise.
10-20% of men experience ED after focal therapy – much lower than whole-gland treatment (20-50%). IRE may have the lowest rates.
Medicare and many private insurers cover cryotherapy and HIFU for prostate cancer. Coverage for FLA and IRE varies.
20-30% need repeat treatment within 5 years (either repeat focal therapy or whole-gland treatment).
Yes – salvage whole-gland treatment (surgery or radiation) is possible if cancer recurs. However, it may be more technically challenging.
No – cryotherapy and HIFU are FDA-approved for ablation of prostate tissue, not specifically for cancer. Focal therapy is considered an alternative treatment.
Choose a centre with extensive experience in focal therapy, MRI-guided targeting, and long-term follow-up data. Ask about their recurrence and complication rates.
Disclaimer: This information is for educational purposes. Focal therapy is not a standard treatment for all prostate cancers. Discuss with a urologist at Vivekananda Hospital to determine if you are a candidate.