Magdy M. Hassouna1,2
1Department of Urology, Toronto Western Hospital, University Health Network, 2University of Toronto, Ontario, Canada
Principle: High intensity focused ultrasound (HIFU) technology uses an ultrasound beam generated by high power transducer to generate heat. When the beam is focused on the prostatic tissues, it results into necrosis of the prostate without damaging the surrounding tissue.
Historical: The technology has been developed in late ‘80 in Europe. In 1993, HIFU was applied in clinical cases of human prostate cancer. In 1996 a European multicenter study on the efficacy and safety of the HIFU was published. In 2003 the Canadian Health Authority has approved HIFU as safe method for treating localized prostate cancer. HIFU is presently used to treat prostate cancer in Europe, Russia, Australia, Canada and South Korea.
Indications:
Localized prostatic cancer (T1–T2)
Not candidates for radical prostatectomy due to co-morbidity or high surgical risk patient
Alternative treatment to radiotherapy
Local recurrence following radical prostatectomy
Local recurrence following radiotherapy and/or brachytherapy.
Procedure: The prostate size should be within 30-35gm size, with an antero-posterior diameter <24 mm. Those patients with >35 gm size prostate are advised to have a TURP prior or concomitant with the HIFU treatment. The treatment is done under spinal or epidural anesthesia with IV sedation to minimize movement. It may last anywhere from 1 to 3 hours depending on the size of the prostate.
At the beginning of the procedure the patient is catheterized and positioned on his right side. After a small probe has been placed inside a liquid-filled latex balloon it is inserted into the rectum. This liquid keeps a constant temperature at the rectal wall throughout the treatment. The urologist maps the outline of the prostate treatment zone using the ultrasound component of the probe. Then 400 to 600 pulses of high intensity focused ultrasound are delivered to the prostate. This process effectively necroses the targeted tissue. The catheter remains post procedure for 7-14 days until the swelling diminishes.
Computer controlled firings result in precisely moving the focal point in order to ablate the whole prostate.
Immediate Post Treatment: Patients usually go home the same day as the treatment and in most cases resume a normal diet the same evening. Prophylactic antibiotics are prescribed after the procedure. Post procedure infections are not common with HIFU. Immediate post treatment complications include mild bleeding in the beginning of micturition, frequent and sometimes urgent micturition, type 1 or 2 urinary stress incontinence and elimination of necrotic debris. These complications are usually transient and self-limited.
Reported Adverse Effects: HIFU is a very safe procedure with no reported mortality and minimal morbidity. Data from the last 100 treatments in the Munich study of 315 HIFU treatments reported in 2000 provides the following incidence of adverse events:

Treatment Follow Up: PSA levels are performed initially and every 3 months post-HIFU. After 12 months, a biopsy is performed to confirm that the treatment has been successful. If the biopsy is negative and the PSA level is very low, the PSA only needs to be performed every 6 months.
If the PSA reading does not return to very low levels a repeat biopsy can be performed. If this biopsy shows any tumor (approximately 10% of the cases) a second HIFU session is conducted. If biopsies are negative but the PSA rises additional therapy may be needed.
Long-term Follow-up Results: A 5-year experience was reported on 146 consecutive T-1/T-2 prostate cancer patients with a PSA level of 15 ng/ml or less. The patients were treated with HIFU in Germany, between October 1997 and November 2002.
The median PSA nadir achieved after 3 months was 0.07 ng/ml and the median PSA level after a follow up of 22 months was 0.15 ng/ml. 93.4% of all patients had negative biopsies:

Presented at the: 18th Saudi Urological Conference King Abdulaziz University Hospital 20-23 February 2006 (21-24 Muharram 1427)