To summarize the methodology, the authors enrolled 115 men with low and intermediate-risk clinically localized prostate cancer: organ-confined prostate cancer (≤T2b, PSA ≤15 ng/ml, Gleason Grade Group 1-2). These patients were accrued and treated at 13 centers in the United States, Europe, and Canada. Patients received whole-gland prostate ablation with sparing of the urethra and urinary sphincter. The primary endpoints were safety and PSA reduction at one year. Secondary endpoints included one-year prostate volume reduction, mpMRI changes, and 10-core biopsy positivity. At two-years, the authors assessed outcomes including adverse events, quality of life (IPSS, IIEF, EPIC), and PSA stability.
Among the 115 patients, median (IQR) age was 65 (59-69) years. Disease characteristics were consistent with intermediate-risk disease in most: median PSA was 6.3 (4.6-7.9) ng/ml, with Grade Group ≥2 (GG2+) disease in 72/115 men (63%). The median ablation zone was 40 (32-50) cc with 98% thermal coverage and ±1.4 mm spatial precision on MRI thermometry. Median treatment time was 51 (39-66) min.
Assessing the primary safety endpoint, the authors found transient grade 3 adverse events in 9 men (8%), all of which resolved by 1 year. There were no rectal injuries or Grade ≥ 4 events.
Assessing secondary endpoints, they found median prostate volume decreased from 37 to 3 cc on MRI at 1 year and GG2 disease was eliminated in 54/68 (79%) men with 72/111 (65%) had no evidence of any cancer. Salvage radical prostatectomy was performed in three men with residual disease on biopsy.
PSA and quality of life data are immature with available data on 48 of 115 patients. Median PSA decreased 95% to a nadir of 0.30 ng/ml which subsequently rose to a small degree over time (0.53 ng/ml at one year and 0.68 ng/ml at 2 years). Median IPSS was unchanged from 7 to 6 at one year and 5 (n=47) at two years. Moderate urinary incontinence (Grade 2, pads) was reported by 3 patients (2.6%) at one year, with no new incontinence at two years. The rate of moderate erectile dysfunction (Grade 2, responding to PDE5) was 23% at one year, with one new onset at two years. Median change in IIEF-5 recovered from -3 at one year to -1 (n=46) at two years. Erections sufficient for penetration (IIEF Q2 ≥ 2) were maintained by 69/92 (75%) at one year, and for the patient subset with two-year follow-up, by 25/37 (68%) and 23/37 (62%) at one and two years, respectively.
In this two-year follow-up on the TACT trial of MRI-guided transurethral ultrasound ablation (TULSA) in men with localized prostate cancer, the authors have shown the feasibility of this approach as well as its relatively low toxicity and stable quality of life.
Authors: Scott Eggener*, Michael Koch, David Penson, Christian Pavlovich, Joseph Chin, Yair Lotan, Steven Raman, Gencay Hatiboglu, Aytekin Oto, James Relle, Jurgen Fütterer, Marc Serrallach, Axel Heidenreich, Masoom Haider, David Bonekamp, Temel Tirkes, Sandeep Arora, Allan Pantuck, Gregory Zagaja, Michiel Sedelaar, Katarzyna Macura, Daniel Costa, Thorsten Persigehl, Andrei Purysko, and Laurence Klotz
Written by: Christopher J.D. Wallis, Urologic Oncology Fellow, Vanderbilt University Medical Center Contact: @WallisCJD on Twitter at the 2020 American Urological Association (AUA) Annual Meeting, Virtual Experience #AUA20, June 27- 28, 2020