Transurethral ultrasound ablation is a promising treatment for prostate cancer, with better outcomes and fewer side effects than traditional treatment, according to 3-year outcomes from the follow-up study of the TULSA-PRO® Ablation Clinical Trial (TACT).
The findings of abstract No. 111, “Pivotal Trial of MRI-guided Transurethral Ultrasound Ablation in Men with Localized Prostate Cancer: Three-Year Follow-Up,” will be presented Monday at 4:12 p.m. as part of Scientific Session 11, Men’s Health 2.
The robotically driven TULSA-PRO (Transurethral Ultrasound Ablation Procedure) system uses magnetic resonance imaging (MRI) to direct ultrasound and ablate part of or the entire prostate. This is a single-session outpatient treatment for patients able to undergo anesthesia.
Prostate cancer is the second-leading cause of death in men in the United States, after lung cancer. About one in eight men will be diagnosed with prostate cancer and one in 41 will die, according to the American Cancer Society.
The prostate-specific antigen (PSA) blood test is used to detect prostate cancer, but it misses some cancers and identifies other cancers that may not have needed treatment.
“Every other cancer has a well-worked-out algorithm, but prostate doesn’t have one,” said presenter Steven Raman, MD, director of prostate MR imaging and interventions and the UCLA Prostate MR Imaging Research Group at the David Geffen School of Medicine at UCLA. “There’s the PSA screening, which is good but not great. Elevated PSAs detect about 70–80% of prostate cancers.”
However, in any given individual, an elevated PSA has an 80% chance of being a false positive, Dr. Raman said.
“So then, you’re left with ‘now what?’ Prior to 10 years ago—or even now—patients would then be subjected to a random biopsy of the prostate—what’s called a “template biopsy.” They take 6–12 core biopsies (six on each side, 12 total) and attempt to hopefully hit the cancer, if there is a cancer,” Dr. Raman explained.
These biopsies detect only about 40–50% of the cancers and do not provide a true risk assessment of the cancer. “More than half the time there is an error in the diagnosis in terms of how much cancer and how aggressive the cancer is,” Dr. Raman said.
In the TACT study, 115 men with organ-confined prostate cancer across 13 centers underwent whole-gland ablation sparing the urethra, bladder neck and urinary sphincter. Primary endpoints were safety and PSA reduction at 1 year. Secondary endpoints were prostate volume reduction, multiparametric MRI and 10-core biopsy at 1 year; and quality of life, PSA and salvage to 3 years.
In 63% of the men, the median PSA was 6.3 (range, 4.6–7.9) ng/mL, with GG ≥2 disease. At 1 year MRI and biopsy, median prostate volume decreased from 37 to 3 cc, GG2 disease was eliminated in 79% of the men, and 65% had no evidence of any cancer.
“The results have been very encouraging: Almost 90% of men have had no evidence of prostate cancer even at 3 years,” Dr. Raman said. “About 13% had some cancer, either a new tumor or a tumor that was not ablated properly. But we’ve also since refined how we treat men for prostate cancer. In that trial we didn’t require the use of CT scans to make sure there were no calcifications, and now we do that so we can maximize our efficacy. I think if we repeated this trial our yields would be even higher.”
There were fewer side effects of incontinence and impotence compared to surgery and radiation. Impotence rates were most acute in the first 3 months; in 83% of patients they returned to baseline, Dr. Raman said. Rates of incontinence were less than 5%.
“It’s a very compelling technology because it uses a lot of radiological skills that very few other specialties have,” Dr. Raman said, “so it’s a great opportunity for interventional radiologists to either go it alone or partner with physicians to offer this novel and unique prostate cancer treatment to their patients and increase their referral base.”
