High Intensity Focused Ultrasound (HIFU)
Medically reviewed by Dr. Paul Song M.D
One of the newest therapy options for treatment of prostate cancer is HIFU, or high intensity focused ultrasound. HIFU is a radiation-free therapy that has been approved by the Food and Drug Administration for “prostate tissue ablation, which means it can be used to treat prostate cancer, although the approval is not specifically for that,” according to Michael Koch, MD, chairman of the department of urology at Indiana University. Thus far, two types of HIFU systems have garnered the FDA’s okay: the Sonablate 450 (approved October 2015; Koch was a trial investigator) and Ablatherm HIFU (November 2015).
Although HIFU is relatively new to the prostate cancer treatment scene in the United States, the technology has been available in Europe, Asia, and elsewhere around the world for more than 15 years, where it has been used to manage benign prostatic hyperplasia, localized whole-gland prostate cancer, and recurrent prostate cancer. According to SonaCare Medical, which developed the Sonablate 450, more than 50,000 men have been treated with HIFU for prostate cancer globally. Now men in the United States will have access to this therapeutic approach.
Who Is a Good Candidate for High Intensity Focused Ultrasound (HIFU)?
Men who have localized prostate cancer can be candidates for HIFU. In a 2015 review in the Polish Journal of Radiology, the authors noted that HIFU is indicated for men who are not candidates for prostatectomy because of general health issues, age, or a preference to not undergo surgery. In addition, HIFU can be used for men who have not responded to or have recurrent prostate cancer after radical prostatectomy, hormone ablation, or radiation therapy.
Dr. Koch remarked that HIFU is appropriate “as an alternative to surgery or radiation, and it can be also be used in surveillance patients whose disease is progressing.”
How Is HIFU Performed?
HIFU uses ultrasound instead of radiation to treat certain types of cancer, including those affecting the prostate, kidney, bladder, pancreas, and liver. The high frequency sound waves emitted from a HIFU device have the ability to kill cancer cells associated with a single tumor or part of a large tumor. HIFU is not appropriate for cancer that has spread (metastasized) beyond one site in the body.
Men who undergo HIFU for prostate cancer can expect a scenario similar to the following. Patients disrobe and lie on their side on a treatment table. The HIFU machine has a transrectal probe, which is guided gently into the rectum. This procedure is performed under either spinal or general anesthesia and takes 2 to 3 hours to complete.
Sonablate 450 utilizes specialized software that allows the clinician to pinpoint the targeted treatment areas while sparing surrounding tissue and to track treatment with advanced real-time ultrasound imaging and simultaneous displays to a monitor. The Ablatherm HIFU uses real-time 3-dimensional imaging, which allows the clinician to precisely deliver the ultrasound and monitor the progress of the ablation.
The ultrasound waves are sent through the rectum walls, where they generate sufficient heat to destroy cancerous prostate cells. HIFU is designed to destroy prostate cancer cells while also preserving the integrity of the prostate gland, which minimizes the occurrence of side effects.
How Does HIFU Compare with Prostatectomy?
Limited research has compared HIFU and prostatectomy. However, several benefits are clear, not least of which is the lack of incisions, which results in fewer complications, less discomfort, and the ability to return to normal activities sooner. Prostatectomy is a surgical procedure that is performed in an operating room while HIFU is an outpatient procedure. While HIFU is limited to destroying the cancerous tissue in the prostate, prostatectomy involves removing the entire gland.
In a matched pair comparison study of 588 men treated between 2000 and 2005 with either HIFU or prostatectomy (294 in each group), researchers observed that at nine years, the overall, cancer specific, and metastasis-free survival rates were similar between the HIFU and prostatectomy groups; namely, 89%, 97%, and 94% vs 89%, 97%, and 97%, respectively.
Gelet A et al. Radical prostatectomy versus high intensity focused ultrasound for localized prostate cancer: a matched pair comparison. Journal of Therapeutic Ultrasound 2015; 3(Suppl 1): O56