High-intensity focused ultrasound, or HIFU (pronounced HIGH-foo), is a promising technology for noninvasive tumor ablation that heats cancerous prostate tumors to near-boiling temperatures. Its potential clinical impact is indeed significant. But given the lack of long-term clinical data, Johns Hopkins advises caution.
Image-guided HIFU procedures could permit the ablation of tumors (not only in the prostate, but also in the liver and lung) without the need for surgery or even an incision. This form of treatment has the potential to minimize side effects -- incontinence and erectile dysfunction -- and improve quality of life for prostate cancer patients while offering a rapid recovery and return to daily activities.
“HIFU is the next frontier in prostate treatment,” said John C. Rewcastle, Ph.D., Adjunct Assistant Professor of Radiology at The University of Calgary and medical director of EDAP, a manufacturer of Ablatherm, a HIFU device. Dr. Rewcastle is directing ongoing HIFU prostate cancer studies in Europe and the United States. “HIFU has the ability to answer the over-diagnosis and over-treatment questions that now surround prostate cancer treatment.”
There are currently two HIFU devices for the treatment of prostate cancer: Sonablate (Focus Surgery, Inc., Indianapolis, Indiana) and Ablatherm (EDAP, Lyon, France). Although both devices are approved in Europe, Mexico, Canada, and the Far East, they are available in the U.S. for prostate cancer treatment only as part of ongoing Phase II/III trials to assess their safety and efficacy.
Cancer cure rates are the primary consideration in any prostate therapy, whether it entails surgery, radiation, or high frequency sound waves. Since HIFU is such a new therapy for prostate cancer, and the pool of treated patients is relatively small, there is not yet a rich source of data to draw upon.
A five-year follow-up study from urologists at the University of Regensburg in Germany was published in 2004 in the journal Urology (“High-Intensity Focused Ultrasound for the Treatment of Localized Prostate Cancer: 5-year Experience”). From the pool of 137 patients, the doctors reported that 93% had negative biopsies following HIFU therapy for prostate cancer; 87% of all patients had constant PSA levels of less than 1 ng/ml; and only two patients had PSA levels that surpassed 4 ng/ml.
The jury's still out … While HIFU is a technology with considerable promise, many doctors agree with Dr. Robertson of Duke University who remarked, "Although many centers in Europe have used it and achieve varying results with many patients, there have not been a lot of scientific publications. We are in the dark about how effective this treatment is long term."
H. Ballentine Carter, M.D., Professor of Urology at Johns Hopkins, has performed more than 3,000 radical prostatectomies. His two words of advice for men contemplating HIFU therapy for prostate cancer: “Buyer, beware!”
