Survival Outcomes and Recurrence Patterns Following Focal High-intensity Focused Ultrasound Treatment for Localized Prostate Cancer: Insights on Patient Selection and Lessons Learned

Abstract

Background and objective: Focal therapy is increasingly being used as a treatment for localized prostate cancer (PC). Our aim was to evaluate oncological outcomes, recurrence patterns, and survival after high-intensity focused ultrasound (HIFU), to discuss the lessons learned from our experience, and to propose strategies to enhance patient selection for HIFU treatment.

Methods: Between 2016 and 2023, 113 patients underwent focal HIFU treatment for PC. Follow-up included prostate-specific antigen (PSA) measurement every 3 mo, magnetic resonance imaging, and a control biopsy performed at 6 or 12 mo. Recurrence was categorized on the basis of location (infield or out-of-field) and Gleason grade group (clinically significant [CS] vs non-CS) with stratification by National Comprehensive Cancer Network risk groups. Kaplan-Meier curves were used to analyze survival outcomes, recurrence rates, and the need for retreatment.

Key findings and limitations: Median follow-up was 29 mo and 92 patients (81%) had PSA follow-up for at least 12 mo. Local recurrence was observed in 34 patients (37%), which was CS in 16 (17%). The CS recurrence-free survival rate at 3 yr was worse for subgroups with high-risk or unfavorable intermediate-risk disease in comparison to the group with favorable intermediate-risk PC (40% and 53% vs 85%; log-rank p < 0.01), with a higher rate of out-of-field recurrence in the high-risk group. The Kaplan-Meier retreatment-free survival rate estimate was 71% at 3 yr. Sixteen patients (17%) underwent salvage local treatment. Study limitations include the small cohort size and relatively short follow-up.

Conclusions and clinical implications: HIFU is a promising alternative for localized PC in well-selected patients. However, patients with high-risk or unfavorable intermediate-risk PC are more likely to experience treatment failure.

Patient summary: We examined cancer control outcomes after high-intensity focused ultrasound for localized prostate cancer. We found that the rate of cancer recurrence was higher for patients with higher-risk disease. However, this treatment is a feasible and acceptable option for patients with intermediate risk.

Keywords: Focal therapy; High-intensity focused ultrasound; Prostate cancer.