What is HIFU ?
HIFU, which is short for High Intensity Focused Ultrasound, is a state-of-the-art technology acoustic ablation technique that utilizes the power of ultrasound to destroy deep-seated tissue with pinpoint accuracy for treatment of prostate cancer. HIFU focuses sound waves in a targeted area which rapidly increases the temperature in the focal zone causing tissue destruction.
In most cases, HIFU is a 1-4 hour, one-time procedure performed on an out-patient basis under spinal anesthesia. Unlike radiation, HIFU is non-ionizing; this means that HIFU may also be used as a salvage technique if other prostate cancer treatments fail.
About High Intensity Focused Ultrasound (HIFU)
- HIFU with the Sonablate® 500 is a non invasive acoustic ablation technique.
- Acoustic ablation uses intersecting, precision-focused ultrasound waves to raise the temperature of the target tissue to more than 80 to 98 degrees Celsius in three seconds, effectively destroying the tissue.
- Ultrasound energy is non-ionizing “clean energy” that does not affect tissue surrounding the target zone, as opposed to radiation therapies.
- In approved countries, HIFU can be given in one to three hours on an outpatient basis with spinal or general anesthesia.
- HIFU is being studied around the world to treat all types of cancer and soft tissue diseases such as uterine fibrosis, breast cancer, liver cancer, pancreatic cancer, and kidney cancer.
- The Sonablate® 500 is approved in many countries outside the U.S. as an image-guided acoustic ablation device developed by Focus Surgery, Inc. (Indianapolis , U.S.A.) for prostate disease therapy.
- The technology behind the device originated at the Indiana University School of Medicine in Indianapolis in the 1970s. It was further developed in leading research centers across the globe.
- In 2001, The Sonablate® 500 received its CE Mark for European distribution and its MHW approval for Japan. It is also approved for use in Canada, India, China, Australia, Japan, Costa Rica, South Africa and the Caribbean.
- Recent studies in Europe have also shown promising results one year following treatment with a lower incidence of erectile dysfunction and urinary incontinence than reported in studies of other therapies.
- In countries where it is approved, the Sonablate® 500 allows a trained urologist to visualize the prostate and plan and monitor the therapy in real time, ensuring maximum precision, flexibility, safety, and control for the clinician.
HIFU energy targets tissue in the prostate in the same way that sunlight focused by a magnifying glass can burn a leaf. When a magnifying glass is held above a leaf, the sun’s rays intersect beyond the lens and cause the leaf to burn at the point of intersection.
If you were to insert your hand into the near or far-field area of the sun light’s point of intersection, there would be no significant heat felt or harm caused. However, if you place your hand at the point of intersection you will be quickly burned.
The scientific principles at work in this example are the same as those with HIFU. The energy source is the only difference. Instead of light as the energy source, HIFU utilizes sound. Instead of a magnifying glass, HIFU uses a transducer. Just as the individual sunray is harmless to the hand, and individual sound wave is harmless to the healthy tissue it travels through.
Will I be Incontinent?
In the first patients treated with Ablatherm® HIFU approximately 1 in 12 experienced either Type 1 or Type 2 incontinence. Type 1 incontinence is the leakage of urine with marked straining. Type 2 is the leakage of urine with mild to moderate straining. Both types of incontinence are manageable with medications and pelvic floor exercises and, if present, last only one month on average. Fortunately, in almost all cases these types of incontinence are temporary. Recent advancements in Ablatherm® HIFU have resulted in even fewer cases of initial Type 1 and Type 2 incontinence. Importantly, there are essentially no total, severe incontinence cases (Type 3) reported unless patients have had previous radiation or surgery.
Will I be Impotent ?
Forty percent of patients retain normal erectile function after treatment. This compares favorably with patients undergoing radical surgery. In those patients specifically treated with nerve sparing techniques, erectile function is retained in over 80% of cases. In addition, the majority of patients who suffer erectile dysfunction following treatment by Ablatherm® HIFU will respond to oral medications (Viagra, Levitra, Cialis). Peer reviewed journal articles now support the use of these oral medications after treatment to enhance healing. Fortunately, many patients regain potency 6 to 12 months after treatment.
Do I Need Further Tests?
A quarterly measurement of the PSA is recommended for the first two years, and biannual tests are recommended in years three and four. Thereafter we recommend an annual PSA test. Three to six months after the treatment the PSA should be reduced to almost undetectable levels.
If the PSA level is undetectable, no prostate biopsy is necessary. If the PSA reading does not return to very low levels, a repeat ultrasound and biopsy can be performed. If this biopsy shows residual tumor (approximately 3% of Canadian cases), a second Ablatherm® HIFU session can be conducted. A major advantage of Ablatherm ® HIFU is that it is repeatable and does not preclude future treatment by any other treatment options. A bone scan and Cat Scan would also be ordered. If biopsies are negative but the PSA rises, additional therapy may be prescribed.
Usually no hospital stay : – Because anesthesia is used, a short observation period is required. However this procedure is typically performed as an outpatient procedure. But, four or more night stay is recommended in the patients from foreign countries.
Precise : – The HIFU energy can be precise to the millimeter in its destruction and therefore minimize collateral damage to nearby tissue and structures.
Lower complications and side effects : – Because the treatment is precise and bloodless, there is nearly no incontinence and a low rate of impotence, 19% (October, 2007). This is true of all HIFU users, because of the clear and precise image guided throughout the therapy.
Recovery time : – While all these procedures have side effects, HIFU typically does not stop you from going on with your life. Because there is no cut to heal, no fatigue, and no soreness from the placement of needles, you can be back to your daily activities the next day.
Repeatable: – Radiation and Chemotherapy can only be done a certain number of times before they become toxic to the body. Surgery creates too much scar tissue to re-operate on a patient. However, HIFU destroys tissue with safe and precise heat energy. This can be done several times. A few patients have been treated up to 4 times with HIFU.
Can be used before or after other treatments : – Unlike most other procedures, HIFU can be done before or after other treatments. All treatments run the risk of having the cancer return. Most of these procedures either could not be repeated or the chances of side effects increase dramatically when mixing treatment options. In opposite, HIFU can be used before or after other treatments without increasing potential side effects.
Before HIFU Treatment
Patients are given two enemas two hours prior to the procedure. It is very important that the patient does not move during HIFU thus patients are given a light intravenous sedation and a spinal anesthesia.
During HIFU Treatment
There is no pain during treatment, A small probe inserted into the rectum emits ultrasound waves directly to the prostatic tissue. During the procedure, the Sonablate delivers real-time images of the prostate and the surrounding area giving the physician immediate and detailed feedbakc.Treatment time varies but generally lasts one to four hours depending on the size of the prostate.
After HIFU Treatment
Immediately after HIFU there is a one to two hour recovery period at the treatment facility and then you are discharged. Recovery is minimal. A catheter is inserted during the procedure that is usually worn for one to four weeks. People usually are up and walking around within hours after HIFU and can return to a normal lifestyle within a couple of days. Some HIFU patients experience frequency, urgency, mild discomfort or discharge in urinary stream. Studies performed outside the US report that potential side effects may also include urinary stricture (18%)2, retention (0.6%)1, incontinence (0.6%)1, erectile dysfunction (20%)1 and rectal fistula (1%)1