The Fred Hutchinson Cancer Center recently added irreversible electroporation (IRE) to its slate of focal therapy offerings and is the only cancer center in the region to offer IRE, high-intensity focused ultrasound (HIFU) and cryotherapy. This comprehensive approach ensures that all patients who are good candidates for focal therapy can access the most appropriate treatment.
“Patients are increasingly asking about focal therapies because they are less invasive and have fewer side effects than radiation and surgery,” says Fred Hutch urologic oncologist George Schade, MD. “We are working to meet this demand through our multidisciplinary prostate cancer clinic at Fred Hutch.”
Therapies at the Leading Edge of Technology
HIFU and IRE use state-of-the-art technology to destroy cancer cells. Operating systems include:
- Focal One® robotic HIFU system: Focal One uses a rectal probe to target the prostate with a high-intensity beam of sound energy. With robotic positioning, the transducer concentrates ultrasonic energy into a precise area of tissue and destroys it with heat. Outside of this “focal” area, energy levels are low, so surrounding healthy tissue is unharmed. The Focal One offers precision tumor mapping and post-treatment enhanced ultrasound to confirm complete ablation of the tumor.
- NanoKnife® IRE: Under transrectal guidance, NanoKnife uses electrodes inserted through the perineum and into the prostate. An electrical current between the electrodes creates pores in the membranes of surrounding cells. This leads to controlled cell death. IRE causes a precise zone of ablation around the electrodes without using heat.
HIFU and IRE are options regardless of prostate shape or size. Patients rarely require hormone therapy or transurethral resection to shrink the prostate prior to treatment.
Dr. Schade performs HIFU and IRE as outpatient procedures under general anesthesia. HIFU takes about two hours, while IRE takes a little longer to place and test the electrodes.
Less Invasive Procedures Lead to Rapid Recovery
Recovery time is usually just a few weeks with HIFU and IRE. “The most common short-term side effect is swelling of the prostate,” says Dr. Schade. “Patients go home with a catheter to help them urinate until the swelling subsides. Most often the catheter is removed and patients can urinate on their own after about one week. Because IRE is more invasive, it may cause some minor bruising or bleeding at the electrode insertion sites.”
Surveillance after HIFU and IRE includes PSA tests at 6 weeks, 12 weeks and 6 months. Patients also receive an MRI and biopsy at 6 to 12 months to look for residual cancer and confirm the effectiveness of the treatment.
No randomized clinical trials have compared HIFU or IRE to standard treatments.
“Based on prospective single-arm studies and registries, we think that cancer control using focal therapies is similar to what we would expect for surgery and radiation therapy,” says Dr. Schade.
HIFU and IRE Reduce Sexual and Urinary Side Effects
Patients who undergo HIFU or IRE have a lower risk of sexual, urinary and bowel side effects.
Among men who had normal sexual function before treatment, about 85% who received HIFU or IRE retained sexual function versus 40% to 80% after surgery. For radiation therapy, long-term sexual outcomes are similar to surgery. How quickly men lose function ranges widely based on whether they receive hormone deprivation therapy with their radiation.
Urinary side effects are also lower with HIFU and IRE compared with radiation therapy and surgery. Long-term urine leakage rates after treatment are:
- HIFU: 1 to 2%
- IRE: 1% to 2%
- Radiation therapy: 2% to 3%
- Surgery: 10% to 15%
Bowel side effects are rare with surgery, HIFU, and IRE. After radiation, 5% to 10% of men can develop long-term fecal leakage.
Eligibility Criteria for Prostate Cancer Focal Therapy
Current research suggests that 25% to 40% of men with prostate cancer are potential candidates for focal therapy. Eligibility criteria for HIFU and IRE include:
- Localized, unilateral prostate cancer
- Gleason score of 6 or 7 (or Gleason 8 for select elderly men with a good life expectancy)
- MRI-visible disease to aid in treatment planning (ideally)
- No evidence of seminal vesical involvement on biopsy and/or MRI
HIFU and IRE may also be an option for men who have localized recurrent prostate cancer after radiation therapy.
Evaluating Patients for Focal Therapy with a Repeat MRI and Biopsy
Dr. Schade evaluates patients with an MRI (if they have not had one) and repeat biopsy to ensure they are good focal therapy candidates.
"I find that about one-third of men evaluated for focal therapy have a higher-grade cancer or more extensive involvement of the prostate than the original tests showed," he says. “If we need to treat a larger area of the prostate or if both sides of the gland are affected, I usually recommend surgery or radiation. We have more data supporting those treatments and side effects are more similar.”
Selecting HIFU vs. IRE vs. Cryotherapy
If a patient is a good candidate for focal therapy, Dr. Schade’s first choice for primary treatment is commonly HIFU because it is less invasive. After radiation therapy, IRE is typically a better option.
“Calcifications, which are common after radiation therapy, and brachytherapy seeds interfere with HIFU sound waves,” says Dr. Schade. “When calcifications are present, cryotherapy used to be our best option. Now, IRE is replacing cryotherapy and is our preferred choice for salvage therapy.”
Prostate Cancer Care at Fred Hutch
Fred Hutch offers complete, coordinated care for all types of prostate cancer at our dedicated Prostate Oncology Center, located at UW Medical Center — Montlake.
Dr. Schade is a key member of the prostate cancer multidisciplinary team at Fred Hutch. This team evaluates each patient and recommends a personalized treatment plan that may involve one or more treatment types, including focal therapy.
To consult with Dr. Schade or another prostate cancer specialist, call 1.800.489.3627.
Genitourinary and Bladder Cancer Patient Referrals, Contact:
Phone: 206.606.8300
Fax: 206.606.2216
