One in eight men will develop prostate cancer in their lifetime. Surgery to treat the disease can lead to unwelcome side effects.
A minimally invasive alternative that avoids surgery is now available in Tarrant County.
KERA’s Sam Baker talks to urologist Dr. Parth Shahof Texas Health Southwest about HIFU or high-intensity focused ultrasound.
What is HIFU?
HIFU is a technology that's been around for about a decade, if not a little bit longer, and it's an ultrasound-driven therapy that can destroy tissue.
How does this work with prostate cancer tissue?
The prostate is an organ that sits between the bladder and the inside of the penis or the urethra. And it essentially, you know, functions in sexual health and urinary health.
So when cancer develops, the modality of treatments includes surgery: removing the whole prostate or irradiating the entirety of a blocked prostate.
Using technology like HIFU or high-intensity focused ultrasound, we can pinpoint the energy of the ultrasound to specific parts of the prostate, thereby avoiding many of the major side effects and the quality of impact that the traditional treatments cause for our patients.
We use real-time intraoperative ultrasound to determine the depth of tissue penetration of the energy, and where to focus the energy. So, it's a real-time image-guided treatment of prostate cancer cells.
How and where do you target the tissue?
The procedure is done under anesthesia. There is an ultrasound probe that is inserted within the rectum. We transmit ultrasound waves through the rectal wall, through the surrounding tissues, and into the prostate. And now only where all these sound waves localize is where heat is generated and tissue death occurs.
When we put the ultrasound waves through the tissues of the rectum, they won't converge at that point. We pinpoint an area within the prostate where the sound waves should meet. And that's where tissue death occurs.
It's all done by mapping out the prostate using imaging. When we capture that image we can use that to extrapolate the length, to which must be reached by the waves. Then, using a lot of physics involving length and distance calculation, the machine creates an algorithm for where the sound waves need to go and where they need to meet.
Using heat around areas of tissue sounds as if there might be some pain or discomfort during or after the procedure.
Patients don't have a lot of pain after the procedure.
The discomfort typically involves using a catheter to drain the bladder of urine. When we destroy certain portions of the prostate with heat or energy, there is a reactionary inflammation that happens. That can lead to a temporary slowing of urinary stream, and to prevent that from having a medical impact on a patient, we leave a catheter to help drain the bladder.
The catheter is temporary, usually for a few days after the procedure. So that ends up being the most, annoying, symptomatic part of the procedure. But physical pain, like a cutting pain from a scalpel or an incision, is not something that patients experience.
Beyond that, are there any cons to this procedure?
Not every patient is eligible to be treated with HIFU. Only certain patients will meet the appropriate criteria so we can ensure that they're getting a good cancer control option, as well as maximizing their quality of life.
Who would those patients be?
Your prostate has to be a certain size, so we can allow those soundwaves to penetrate as deep as they need. They also need to have prostate cancer in the low or middle-risk category in terms of aggressiveness. This will be determined by what the biopsy results are.
I was under the impression that unless you have an aggressive case, prostate cancer develops slowly enough that some doctors will opt to monitor it for a while before taking further action. At what point would you even consider HIFU?
Active surveillance makes sense for patients who have localized prostate cancer, but who don't have an aggressive case. The goal is to defer or delay treatment, often for years, before the disease changes.
About 50 to 60% of men on active surveillance do transition to a treatment over five years. Given the fact that the cancer biology may continue to change over time, during those five years, those men are showing up to get blood tests to make sure that the prostate number or the PSA is staying the same, but additionally also getting some imaging through MRI's and also additional biopsies to confirm that the tissue is not changing its biology.
So active surveillance is a great treatment strategy. Half of my patients are on that treatment protocol. But as you can see, if we're going to do this correctly and make sure that we're not going to allow the cancer to escape on us, it requires thoughtful follow-up and maybe biopsies and imaging.
So, patients for HIFU would have low or middle-risk cancer. They don't want to undergo active surveillance because showing up twice a year for blood tests, an imaging test every year, or maybe a biopsy every couple of years isn't something they would want to do in perpetuity.
Other good candidates would have that middle-risk category. Active surveillance may not be a great idea for them, because the cancer is slightly more aggressive and there's a chance for it to spread over time. And those patients perhaps don't want to have the whole prostate removed because, again, they don't want the sexual side effects or the urinary side effects and they don't want to end up having radiation because, even though it's good, it can have long term side effects and impact on health in the future.
Are there any side effects from high flu?
Side effects are typically temporary. Some men notice for the first 24 to 48 hours that they have changes in their urinary stream. And that's pretty much it in terms of physical side effects.
In terms of erectile function compromised, the chances are low, about 10%, that they can develop erectile dysfunction or ejaculatory dysfunction. However, compared to surgery or radiation, where those chances are, say 60 to 80%, that's a significant gain in benefits.
One in eight men are diagnosed with prostate cancer in their lifetime. Why is that disease so common?
Prostate cancer is prevalent. And as men age, it's a somatic mutation. These mutations occur over time. Cancer happens when these mutations don't get deleted by your body, your immune system, etc. So, you know, the prostate being an organ that constantly turns over and grows, that's what it's designed to do biologically.
So that's where the incidence of cancer of prostate cancer increases over time as those cells are continuously turning over, at the same rate, no matter where we are in our aging process. And at that point, you know, a mutation can lead to continuous growth.
Prostate cancer is the most common solid body cancer that develops in men and any ethnicity. The morbidity or the harm that's caused by prostate cancer can be low if caught early and we can monitor it. But with a lot of men getting mixed messages about who should be screened, we're losing the fight against prostate cancer in some ways, because we're not going through the early detection that we need to with our regular checkups.
This new technology is great, but I think we should focus on prevention and early detection, so we can ensure that men are not dying because of prostate cancer, which is what we've seen over the past five or ten years. Less and less focus has been paid on prostate cancer screening.
RESOURCES:
Thermal and mechanical high-intensity focused ultrasound: perspectives on tumor ablation, immune effects and combination strategies
Transrectal high-intensity focused ultrasound for the treatment of prostate cancer: Past, present, and future
Key Statistics for Prostate Cancer
