The minimally invasive MRI-guided transurethral ultrasound ablation (TULSA) for prostate cancer is associated with better safety and periprocedural outcomes compared with robotic prostatectomy, according to the early results of the phase III CAPTAIN trial.
At 6 months, 50 percent of patients who underwent TULSA met the primary composite safety endpoint of preservation of pad-free continence and erections sufficient for penetration as opposed to only 24 percent of those who underwent robotic prostatectomy (risk ratio, 2.1; p<0.05), reported lead study author Dr Laurence Klotz from the University of Toronto, Toronto, Canada. [EAU 2026, abstract LB005]
A breakdown of the composite safety endpoint showed that around 85 percent of patients had preserved pad-free urinary continence and more than half could achieve erections satisfactory for sexual intercourse in the TULSA arm. The corresponding percentages of patients in the surgery arm were less than 50 percent for both endpoints.
“These are early results. One would expect both of these parameters to improve over time with both treatments,” Klotz noted.
Perioperative outcomes
“TULSA delivers directional thermal ultrasound under real-time MRI thermometry control to precisely treat prostate tissue while sparing genitourinary function,” Klotz said.
The technique was noninvasive and used existing orifices, so there was no blood loss, he added. In contrast, there was moderate blood loss of 150 mL with prostatectomy (p<0.0001).
Additionally, TULSA was performed as an outpatient procedure, and the length of stay was shorter at 0.3 days as opposed to 1.1 days with prostatectomy. TULSA was associated with reduced pain in the first week, although the pain scores were similar between the two treatment arms at the 10-day mark.
With regard to patient-reported overall health at day 30, assessed using the EQ-5D-5L visual analogue scale, there was less decline with TULSA vs surgery (p<0.05). Klotz noted that the overall health score even went above baseline with TULSA, “probably reflecting the patient’s relief at having had his prostate cancer.” In patients who underwent radical prostatectomy, the overall health score remained below baseline up to 30 days.
Compared with the surgery arm, the TULSA arm also had significantly less time missed from paid employment (median, 10 days compared with 19 days in the surgery arm (p<0.05), with fewer admissions to hospital (0.7 percent vs 6.3 percent) or ICU (0 percent vs 1.6 percent) for complications within the 90-day follow-up.
Oncologic data pending
According to Klotz, data on oncologic outcomes will be available at the 3-year follow-up and periodically reported thereafter up to 10 years.
“The oncologic outcome after TULSA is primarily a function of MRI showing residual disease and biopsy, which is mandated on all patients at 1 year,” he said.
Enrolment feat
Conducted at 23 sites across Europe, Canada, and US, CAPTAIN included 211 men with intermediate-risk primary localized prostate cancer (ISUP 2/3 and PSA ≤20 ng/mL). None of the patients had extra-prostatic disease, target radius of >3 cm, calcifications >3 mm in target volume, and implants causing MRI artifacts.
“This was really a major achievement to successfully accrue more than 200 patients to a prospective randomized trial comparing surgery to an ablation technique at 6 months,” Klotz said.
The patients were randomly assigned to undergo TULSA (n=148) or local standard-of-care prostatectomy (n=63), which was mostly robotic. The median age was 63 years in the TULSA arm and 65 years in the surgery arm. The baseline PSA was 6.5 and 7.2 ng/ml, while the prostate volume was 41 and 35 cc in the respective treatment arms.
Learning curve
“[TULSA] is a complex technology,” Klotz said in response to a question about its learning curve.
“The amount of time that the treatment takes comes down steadily over time, out to the first roughly 50 cases. It’s a team-driven treatment which benefits from input from engineers, from the MRI technologists, from the urologist and radiologist, so it’s a kind of composite learning curve,” he added.