Exploring HIFU in Early to Intermediate Prostate Cancer Treatment
Alexander Kenigsberg, MD, discusses a new nonsurgical, robotic-focused ultrasound procedure for prostate cancer.
Alexander Kenigsberg, MD
According to Alexander Kenigsberg, MD, prostate cancer remains a significant health concern for men worldwide, ranking as the most commonly diagnosed malignancy and the second leading cause of cancer-related deaths among men in the US.Conventional treatments like radical prostatectomy and radiation therapy have proven effective in managing the disease; however, they are often linked with morbidity, impacting patients' quality of life with a number of adverse events.
Recognizing the need for less invasive yet equally efficacious alternatives, the field of urologic oncology has witnessed the emergence of innovative focal therapies. Among these, high-intensity focused ultrasound (HIFU) stands out as a promising nonsurgical approach. HIFU works to precisely target cancerous prostate tissue while minimizing damage to surrounding healthy structures.
VCU Massey Comprehensive Cancer Center has become the first institution in Virginia to offer this cutting-edge technology. This outpatient procedure is typically completed within an hour and allows patients to return home on the same day.
“What is great about this procedure is we can see some of the key structures that have to do with erectile function and incontinence and preserve them,” said Kenigsberg, director of urologic oncology at VCU Health Massey Comprehensive Cancer Center, in an interview with Targeted OncologyTM.
In the interview, Kenigsberg provides critical insights into HIFU and how it can be strategically integrated into treatment algorithms for patients with prostate cancer.
Targeted Oncology: Can you provide some background on this new nonsurgical, robotic-focused ultrasound procedure, and what this means for oncologists who work in the prostate cancer space?
Kenigsberg: Prostate cancer is the number 1 most diagnosed malignancy in men in the United States, and it is actually the second leading cause of male cancer death in the United States, about 35,000 men a year. But there’s a huge spectrum of prostate cancer disease. Some [patients] have disease that is not very clinically aggressive, but other [patients], as noted by it being the second leading cause of male cancer death, have very aggressive disease, and then somewhere in between, there is this large pool of [patients] who have something that is not quite the disease that we are comfortable watching, but probably not the really aggressive disease that is going to drive their mortality.
3D rendered medically accurate illustration of prostate cancer: © SciePro - stock.adobe.com
In the last 10 to 15 years, there have been great developments in prostate cancer diagnosis, where we have discovered that MRI is really good at seeing prostate cancer and telling us exactly where it is in the prostate and then helping us to guide our biopsies exactly to that spot, so we make sure that we are accurately characterizing disease. Now, the next logical leap that one might make when realizing that that works is, well, why do we need to treat the whole prostate when someone has prostate cancer, particularly if you're not in this bucket of [patients] who have the really aggressive prostate cancer? And the reason that we are even searching for more accurate and precise treatments is because the current treatments, or the standard-of-care treatments for prostate cancer, are flawed.
We have surgery or radical prostatectomy, which has gotten better over the years, particularly with robotic surgery, but [patients] still suffer with incontinence and erectile issues after that surgery, and there's a surgical recovery associated with that. And then there's radiation, which, again, really good, really effective, but some [patients] can have some urinary and bowel [adverse events] and also can suffer with some of the same issues with erectile function. Also, many [patients] who get radiation have to get hormone shots associated with that, and [those have adverse events].
In recent years, there has been this thought, well, why don't we take an energy source, whether that is heat or freezing or something, disrupt the cell wall of the prostate cancer cells, and destroy prostate cancer. We have brought one of these cutting-edge technologies here to central Virginia, VCU, the Focal One High-Intensity Focused Ultrasound device. It is a same-day procedure where patients come in and we put them to sleep. They do have to go to sleep under general anesthesia, and in about an hour or an hour and a half, we destroy the part of the prostate where the cancer is, and then a safety margin around there. But what is great about this procedure is we can see some of the key structures that have to do with erectile function and incontinence and preserve them.
What are the general criteria for HIFU candidacy in early or intermediate prostate cancer?
We are still in the early days of the focal therapy field. People have been doing it for about 10 to 15 years, but during that time frame, MRI has gotten better, our biopsies have gotten better, and the ablation technologies have gotten better, so it is constantly evolving. As I noted earlier, MRI sees prostate cancer quite well, so most of us who are doing this believe that the right candidate for this has MRI-visible disease. That means someone where we can see it clearly in the MRI, and they have had a biopsy that has targeted that precise location so that we make sure that we are treating the correct patients and not missing a more aggressive disease that requires a more aggressive treatment.
How does this compare with surgery and radiation regarding effectiveness and quality of life?
That is really the ultimate question in this field, and it is something that we are in the process of answering, but it is complicated. We know that it is less morbid than surgery and radiation. [Patients] do better in terms of erectile function and urinary function. But in terms of cancer control, it is almost a slightly different paradigm. What I mean by that is that we think of surgery and radiation as curative therapies. Now, they are not always successful in that, but that is the goal.
Focal therapy, at least at the moment, is more like turning an acute condition into a chronic condition—the idea being that you take this disease, and you surveil these [patients] after you treat them, and hopefully you'll never need to progress to the more morbid treatments of surgery and radiation. There are only a few trials out there that compare these 2 things, and it is tough because the definition[s] of failure [are] different with surgery, radiation, and focal therapy. But there does appear, at least in some of the earlier data, to be some noninferiority in terms of failure in focal therapy. That would mean progressing to further therapy. I tell [patients] that about 25% of them will need a repeat ablation, and about 20 to 30% of them will progress to surgery or radiation within 5 years.
How do you monitor patients for recurrence after this?
That is an interesting and developing space. [Prostate-specific antigen (PSA)] has kind of been the standard for monitoring all sorts of prostate cancer. We would expect a pretty significant PSA reduction, usually of at least 50%, after we perform a focal ablation. We routinely will get MRIs to monitor [patients] 6 to 12 months afterwards, and if there is concern on the MRI, then we will get biopsies. There are some interesting studies out there now using [prostate-specific membrane antigen (PSMA)] PET scans to evaluate this, and that is something we are actively pursuing. We are also working with some novel technologies and developing protocols here to monitor [patients] with that.
Are you able to speak to any of the cost considerations or accessibility of this?
This is something that has become much more accessible. The way the focal therapy field started in prostate cancer was that private urologists were getting these devices and going to the Caribbean, and then [patients] were paying tens of thousands of dollars out of pocket to get these treatments. That was truly the wild west of focal ablation. Now there is a CPT code, so there's a more standardized billing process. Medicare covers it, the VA covers it, and a lot of private payers are starting to cover this.
I think the reason is because there is so much morbidity associated with the standard treatment options that there are a lot of downstream costs associated with surgery and radiation, many of which we will not see with focal ablation. There is an increasing understanding that quality of life is important for [patients with] cancer and survivors. It is becoming more accessible, and as utilization goes up, that is a big part of our mission here at VCU. We have a diverse patient population, socioeconomically, racially, etc, and we want this option to be available to everyone because it is so much less morbid.
How would you say that this fits into prostate cancer treatment approaches?
I think this is a wonderful option for [patients] with intermediate-risk prostate cancer. It depends on your patient population, but we could be talking about this as a very standard-of-care option, potentially in the future, for up to 30% to 40% of [patients] with prostate cancer. There are over 200,000 prostate cancer diagnoses a year in the United States, so it is going to transform care in many ways. This is just the beginning. We are talking about the first 5, 10, 15 years of this field of study. But prostate cancer affects [patients] over decades, so we are going to see a lot more of those.
What are the future directions for this research?
We need to figure out what happens to [patients] not 5 to 7 years out, but 10 years, 15, 20, 25 years. That is not just cancer outcomes; that is also functional outcomes. Is there deterioration over time? How often do [patients] have to retreat? What happens with salvage treatment? We have some evidence that surgery and radiation can be done very safely after focal ablation if it is not successful, but down the line, if [patients] are getting 2, 3, 4, 5 focal ablations, what does that mean? There are a lot of questions about how we follow these patients, what is a true recurrence, what is a clinically meaningful recurrence, when is imaging going to be optimal for finding or following these patients? Do we need to biopsy them regularly? It is an area ripe for investigation and study.
I am part of the Focal Therapy Society. I think that is a great organization that is trying to bring rigor to this space, because there can be a slippery slope when you have a tool of applying it in an inappropriate fashion. We want to do this in a rigorous fashion, where we study our outcomes, and we follow our patients and try to do the best thing for them.
