KEY TAKEAWAYS
- The TACT study aimed to assess 5-Year safety and efficacy outcomes in Low- to Intermediate-Risk PCa patients.
- The result demonstrated an effective long-term cancer control and perceived quality life with minimal side effects.
Magnetic resonance imaging-guided transurethral ultrasound ablation (TULSA) is a prostate treatment that combines ultrasound and Magnetic resonance imaging (MRI) technologies. Ultrasound heats up and coagulates tissue, guided in real-time by MRI. The treatment is fine-tuned using automatic feedback from MRI thermometry, adjusting parameters to match tissue response in the targeted area.
In the interventional study, “TACT,” Scott Eggener and other researchers focused on low to intermediate-risk prostate cancer (PCa) patients who have completed their 5-year follow-up. They shared the results regarding the safety and effectiveness of the treatment after a 5-year period.
The study involved 115 participants from 13 locations across five countries. To be eligible, individuals had to meet specific criteria, including having a PCa stage of ≤ T2b, PSA level of ≤ 15 ng/mL, and Grade Group (GG) 1-2 disease. The study protocol outlined a single whole-gland TULSA treatment that spared the prostatic urethra and urinary sphincter, with no provision for repeat TULSA.
The primary outcomes, evaluated at the one-year mark, focused on PSA reduction and adverse events (AEs). Additionally, histologic control through a 10-core biopsy and prostate volume reduction using multiparametric MRI (mpMRI) were assessed at the one-year mark. Secondary endpoints, evaluated up to five years, included AEs, quality of life(QoL), PSA levels, and the incidence of salvage treatment.
The baseline characteristics of the study population were as follows: the median (interquartile range [IQR]) age was 65 years (59-69), and the median (IQR) PSA was 6.3 ng/mL (4.6-7.9). Among the 115 men, 72 had ≥GG2 disease. At the 1-year follow-up, the median prostate volume decreased significantly from 37.3 to 2.8 cc (92% reduction), and 94 out of 111 men (85%) were free of ≥GG2 disease. By the 5-year mark, the median (IQR) PSA further decreased to 0.6 ng/mL (0.18-1.9) in 68 individuals. Salvage treatment was administered to 25 men (21.7%), including 10 undergoing prostatectomy, 11 receiving radiotherapy, 3 undergoing androgen deprivation therapy (ADT), and 1 undergoing surgery combined with radiation. No unexpected complications were reported.
Early predictors of treatment failure by the 5-year follow-up included the 1-year PSA level (OR=3; CI[1.7,5.4]) and the presence of a visible lesion on 1y mpMRI (OR=12; CI: [4.4, 34]) (both P≤0.001). Failure modes included undertreatment due to issues related to patient selection or targeting errors, as well as misalignment caused by intraprocedural swelling/motion.
Regarding functional outcomes, by the 5-year mark, 92% (61 out of 66) of individuals achieved pad-free continence, and 87% (80 out of 92) maintained erections sufficient for penetration. Grade 3 AEs were observed in 10% of cases (12 men), with no Grade ≥4 events or rectal injuries reported.
The result demonstrated that sustained disease control over a 5-year period following a single TULSA procedure was evident, accompanied by a favorable safety profile. The enduring preservation of genitourinary QoL for this duration was also noteworthy. Identified modes of treatment failure encompass screening and intraprocedural factors. While the pivotal study reflects the initial experience with TULSA, contemporary protocols effectively mitigate the risk of failure.
These protocols incorporate best practices for screening intraprostatic calcifications, which could otherwise result in undertreatment. Additionally, refined strategies for precise device positioning and thermal dose escalation are implemented to address instances of visible undertreatment detected during intraprocedural imaging. Early clinical follow-up and insights from intraprocedural imaging contribute to the prediction of salvage therapy within the 5-year timeframe.
This study is sponsored by Profound Medical Inc.
Source: https://suo-abstracts.secure-platform.com/a/gallery/rounds/18/details/3269
Clinical Trial: https://clinicaltrials.gov/study/NCT02766543
Eggener S, Pavlovich C, Koch M, et al. “PIVOTAL STUDY OF MRI-GUIDED TRANSURETHRAL ULTRASOUND ABLATION (TULSA) OF LOCALIZED PROSTATE CANCER: 5-YEAR FOLLOW UP” Presented at SUO 2023. (Poster: 197)
