Oncological Outcomes of Partial Gland Ablation Using High-Intensity Focused Ultrasound After Additional Confirmatory Transperineal Mapping Biopsy in Men with Prostate Cancer

Background/Objectives: To evaluate whether additional confirmatory transperineal mapping biopsy (TPMB) in men with localized prostate cancer (PCa) alters the treatment plan and outcome of partial gland ablation (PGA) using high-intensity focused ultrasound (HIFU). Methods: We retrospectively reviewed data from 96 patients who underwent PGA using HIFU between January 2020 and June 2022. After multiparametric magnetic resonance imaging (mpMRI), all men underwent transrectal ultrasound (TRUS)-guided, cognitive-targeted biopsy and systematic biopsy. Men eligible for PGA using HIFU first underwent confirmatory TPMB. Any changes in the treatment plan after TPMB were analyzed. Follow-up TRUS-guided biopsy was performed 1 year post-operatively to evaluate oncological outcomes. Clinically significant PCa (csPCa) was defined as Gleason grade (GG) ≥ 2. Results: Among all subjects, the median age (IQR) was 65.0 (60.0–72.0) years and the prostate-specific antigen level was 5.20 (3.71–7.81) ng/mL. The results of both TRUS-guided biopsy and TPMB led to a change in the treatment plan (from unilateral to bilateral PGA) for 13 (13.5%) patients. The 1-year follow-up TRUS-guided biopsy identified PCa in 13 (13.5%) patients, and csPCa in 7 (7.3%) patients. The infield- and outfield-positive rates were 8.3% (8/96) and 3.1% (3/96), respectively, for any PCa, and 3.1% (3/96) and 2.1% (2/96), respectively, for csPCa. Conclusions: Confirmatory TPMB results in better disease identification and localization, thereby affecting the treatment plan and improving oncological outcomes. Therefore, confirmatory TPMB should be considered to establish an appropriate strategy for patients with localized PCa eligible for PGA using HIFU.