Introduction:

MRI-guided transurethral ultrasound ablation (TULSA) is a minimally invasive procedure for prostate ablation, and has emerged as an option for targeted treatment of prostate cancer (CaP). Since the conclusion of our center’s participation in the TACT pivotal study, we initiated a clinical program offering men with localized CaP the TULSA Procedure. Here we contrast outcomes from TACT with single-center outcomes from our clinical program.

Methods:

TACT enrolled 115 men with organ-confined prostate cancer (≤T2b, PSA ≤15 ng/ml, Grade Group 1-2) across 13 centers. Treatment was whole-gland with sparing of the urethra and urinary sphincter. Primary and secondary endpoints included safety, PSA, and prostate volume reduction at one year on MRI. Key differences in our clinical program are focal ablations, with ≥2 cycles per lesion and radiologist and urologist-defined sparing of critical structures when appropriate. Our clinical program prospectively collected data of men with localized CaP who underwent TULSA procedure and were followed with q3 month PSA and prostate MRI at 1 year. After enrolling 3 patients in TACT, we launched our clinical TULSA program in October 2020 and have treated 67 patients to date.

Results:

At baseline, our patients were significantly older than in TACT (median (IQR) 68(65-72) vs 65(59-69) years, p<0.05 and proportion of patients with Grade Group ≥2 was significantly greater in our cohort 79% vs 63%, p<0.05. Compared with TACT, our median (IQR) PSA were not significantly different (6.1(4.3-8.7)ng/mL vs 6.3(4.6-7.9)ng/ml, p=0.97) .

The decrease in both median prostate volume and PSA by 1 year were less in our program relative to TACT (49% vs 91%, p= <0.001; 52% vs 92%, p=0.98). To date, 21 (31%) men have reached 1-year follow-up, and 3 demonstrated imaging evidence of recurrence (PI-RADS ≥3 lesion). Similar to TACT, our rates of Grade 3 adverse events were low (2%, and 8% in TACT). There was no rectal injury or Grade ≥4 event in either the TACT trial or our clinical program. At 6 months follow-up, 73% and 100% of men preserved potency and continence

Conclusion:

Given differences in approach between our current clinical program and the TACT trial (focal versus whole gland), decreases in median prostate volume and PSA from baseline were appropriately less. While follow-up is limited, our experience to date is similar to TACT, as TULSA in men with localized prostate cancer demonstrated effective disease control with low toxicity.

Funding: N/A