Originally published 10/26/2016
When HIFU (High Intensity Focused Ultrasound) was finally approved in the U.S. by the FDA in 2015, it was for whole gland, or radical, prostate cancer (PCa) treatment. Leading up to that approval, some PCa patients who were candidates for prostatectomy held off on surgery, in hopes that the FDA would come through before they missed a treatment window. They were willing to take that chance because HIFU not only had a quick recovery time, it generally has better post-treatment potency rates than surgery. HIFU patients are more likely to regain sexual function, and sooner. Still, up to 61% of patients were disappointed, as the 2016 blog below points out.
By way of update, we cite a 2020 review of published literature on HIFU for PCa. According to He, et al., 18 whole-gland HIFU studies were included in their data analysis.[i] They found incidence of impotence at 3 months after treatment ranging from 30.7% to 65.6%, with an average rate of 44%. (They did not report longer-term rates).
Since then, focal HIFU offers better rates of potency preservation than whole gland HIFU.A paper by Borges, et al. (Jan. 2021) reports their experience with both HIFU and cryotherapy. Their patients were divided into two groups: 195 men had focal treatment and 105 had whole gland treatment. (Though the abstract doesn’t specify how many patients had HIFU or cryo, it’s the extent of treatment that matters.) Pre-treatment (baseline) and post-treatment erectile function were assessed using the simplified International Index of Erectile Function (IIEF-5), In which scores range from 5-25: 5-7 means severe ED, 8-11 means moderate ED, 12-16 means mild to moderate ED, 17-21 means mild ED, and 22-25 means no ED. In the Borges study, there was no difference between the two groups in average IIEF scores. The table summarizes the difference after HIFU:
| Average IIEF-5 score at 3 months | Average IIEF-5 score at 12 months | |
| Focal HIFU | 12 (mild to moderate) | 13 (mild to moderate) |
| Whole gland HIFU | 5 (severe ED) | 9 (moderate ED) |
As you see, those treated with whole-gland HIFU reported worse erectile function, with gradual improvement by 1 year. Whether the treatment was HIFU or cryo, the study underscores that focal therapy is the most important factor in regaining sexual function. Improvements in HIFU technology will likely lead to even better potency rates in the future. Meanwhile, patients planning on whole gland HIFU should discuss reasonable ED expectations with their doctors.
Just as Ponce de Leon sought in vain for a fountain of youth, it appears that the search for a whole gland treatment that will reliably preserve sexual function remains fruitless for the time being. At least, based on medium-term outcomes of whole gland HIFU announced by Dr. Mark Emberton’s team, it sure looks that way.
HIFU (high intensity focused ultrasound) is a noninvasive prostate cancer treatment for localized disease that uses sound waves to destroy the cancer. U.S. patients waited hopefully for FDA approval for well over five years, while HIFU was being routinely offered in Europe, Japan, Mexico, China and many South American countries. Since there’s no surgery or radiation, this outpatient ultrasound-guided treatment was interpreted by many as being better able to spare erectile function as well as continence. The publication of the 5-year (medium term) results involving a cohort of 569 patients at University College London Hospitals and seven other British centers reveals disappointing sexual outcomes.[ii] The study included primary intervention using HIFU as well as re-do HIFU.
Patient ages ranged from 47-87, with the average (mean) age of 65. One hundred sixty-three patients (29%) required a total of 185 repeat HIFU treatments, for a total of 754 treatments. Of those who completed the study and follow-up, there were 161 low-risk patients (28%), 321 intermediate risk (56%) and 163 high risk (14%). Median follow up was 46 months. The 5-year failure-free (no rise in PSA) rates were
Low risk 87% failure free
Intermediate risk 63%
High risk 58%
The main urinary side effects for the total 754 treatments were as follows:
A single urinary tract infection – 58 (7.7%)
Recurrent urinary tract infection – 22 (3%)
The authors report, “Of 206 known to be pad-free pre-HIFU, 183/206 (88%) remained pad free, and of 236 with good baseline erectile function, 91/236 (39%) maintained good function. The main limitation is lack of long-term data.” The researchers note that while cancer control was “acceptable” and there was low risk of urine leakage following treatment, the ED rates were “similar to other whole gland treatments.”
Perhaps one reason for 61% percent experiencing post-HIFU sexual dysfunction has to do with ultrasound guidance. While ultrasound reveals the contours and size of the gland, the fine details of the location of the neurovascular bundles are obscured. This helps explain why the top robotic surgeons have higher rates of nerve-sparing success, since they are able to directly observe the highly magnified anatomy (which differs slightly from one patient to another). Although most HIFU will continue to be done under ultrasound guidance, there is a ray of hope. A new approach called MRgFUS (Magnetic Resonance-guided Focused Ultrasound) uses real-time multiparametric MRI to reveal the anatomy of the gland and the functional tissue characteristics that define the location, size, shape and aggressiveness of the tumor. According to Zini et al. (2012), “This advantage makes MRI the more suitable technique [over ultrasound] for targeting focal cancer lesions in the prostate. In addition, MR thermometry enables the operator to monitor the temperature and amount of estimated tissue damage real time both at the site of ablation as well as in vulnerable areas that have to be protected from ablation.”[iii] Not only will MRgFUS be able to identify and avoid the neurovascular bundles (as clinically appropriate given tumor location) but it is completely noninvasive since there is no transrectal probe. The crystal array that delivers precise sound energy is actually in the table on which the patient lies, and which slides in and out of the bore (tunnel) of the magnet. In fact, at our Center we are excited about the possible benefits of MRgFUS, and are vigilant in tracking developments in this technology since we anticipate offering it.
To sum up, the current HIFU device systems that incorporate transrectal ultrasound guidance appear to deliver cancer control and side effect results similar to other whole gland treatments such as prostatectomy and radiation. While this may be disappointing for the present, we believe there is hope for the future thanks to multiparametric MRI.
NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.
References
[i] He Y, Tan P, He M, Hu L et al. The primary treatment of prostate cancer with high-intensity focused ultrasound. A systematic review and meta-analysis. Medicine (Baltimore). 2020 Oct 9; 99(41): e22610.
[ii] Dickinson L, Arya M, Afzal N, Cathcart P et al. Medium-term Outcomes after Whole-gland High-intensity Focused Ultrasound for the Treatment of Nonmetastatic Prostate Cancer from a Multicentre Registry Cohort. Eur Urol. 2016 Mar 4. pii: S0302-2838(16)00244-X. doi: 10.1016/j.eururo.2016.02.054. [Epub ahead of print]
[iii] Zini C, Hipp E, Thomas S, Napoli A. et al. Ultrasound- and MR-guided focused ultrasound surgery for prostate cancer. World J Radiol. 2012 Jun 28; 4(6): 247–252.
About Dr. Dan Sperling
Dan Sperling, MD, DABR, is a board certified radiologist who is globally recognized as a leader in multiparametric MRI for the detection and diagnosis of a range of disease conditions. As Medical Director of the Sperling Prostate Center, Sperling Medical Group and Sperling Neurosurgery Associates, he and his team are on the leading edge of significant change in medical practice. He is the co-author of the new patient book Redefining Prostate Cancer, and is a contributing author on over 25 published studies. For more information, contact the Sperling Prostate Center.
