High-intensity focused ultrasound (HIFU) can be considered ready for prime time as a treatment for localized prostate cancer considering evidence that it can provide cancer control outcomes comparable to those associated with radical prostatectomy or radiation therapy. The suitability of HIFU as an alternative to traditional options for management of prostate cancer, however, depends on proper patient selection, said Cary N. Robertson, MD.
“HIFU is a bridge treatment that lies halfway between active surveillance and traditional definitive therapies, and it gives us another tool for meeting individual patient needs” said Dr. Robertson, associate professor of surgery (urology) at Duke University Medical Center, Durham, NC.
Dr. Robertson noted that per FDA guidance, the registration trial investigating the efficacy and safety of the Ablatherm-HIFU device only enrolled subjects with low-risk prostate cancer. When the application for approval was first reviewed, however, members of the FDA’s Gastroenterology-Urology Devices Panel expressed concern that the treatment benefit did not outweigh the risks in this population of men who may qualify for active surveillance as initial treatment. This may not apply to high-volume low-risk prostate cancers, however.
“My main message about HIFU’s role for management of localized prostate cancer is that while it can be used to treat men with high-volume, low-risk disease, it is not meant for only that setting,” said Dr. Robertson.
According to Dr. Robertson, optimal candidates for HIFU are men with “low” intermediate-risk prostate cancer who have a small gland (<40 cc) that can be treated without the need for an adjuvant procedure to downsize or debulk the prostate.
“A patient with high-volume Gleason grade 3+3=6 or low-volume Gleason grade 7 (3+4) prostate cancer would be ideal, but HIFU may also be considered for a man with a small focus of higher grade disease,” he said.
One niche for whole-gland HIFU is for a subgroup of men who have comorbidities that make them poor candidates for surgery or radiation therapy. And, when prostate cancer is unilateral, HIFU hemiablation is something that can be considered as an alternative to surgery or radiation therapy by men who are concerned about the functional side effects of those traditional interventions.
“Hemiablation in men with unilateral prostate cancer is probably the future for HIFU because it has a favorable safety profile relative to traditional treatments for prostate cancer. In addition, available data indicate that hemiablation HIFU is associated with acceptable cancer control rates, although follow-up duration in studies of hemiablation HIFU is much shorter,” Dr. Robertson said.