Focal Treatment for Unilateral Prostate Cancer Using High-Intensity Focal Ultrasound: A Comprehensive Study of Pooled Data

Background: Focal therapy for prostate cancer (PCa) remains experimental. Aim of the current study is to review available evidence and perform a pooled analysis exploring oncologic and functional results of high-intensity focal ultrasound (HIFU) focal therapy for the treatment of unilateral PCa. Methods: The National Library of Medicine Database was searched for relevant articles. A wide search was performed, including the combination of following words: HIFU, prostate,'' cancer,'' and focal.'' Overall, 167 articles were reviewed. Of these, seven articles were identified and eligible for the pooled analysis. Data on HIFU hemiablation or focal prostate ablation, oncologic and functional results were pooled from these seven studies that included 366 men with unilateral PCa. Results: In the 366 analyzed cases, mean age was 67 years (95% confidence interval 66-69), and mean preoperative prostate-specific antigen was 6.4 ng/cc (5.5-7.4). Three studies included PCa up to Gleason 7 (3 + 4), three studies did include also Gleason 7 (4 + 3), whereas one study had no limitation in terms of Gleason score. Regarding early complications, low-grade Clavien-Dindo I-II were reported in 26% (16-37), whereas high-grade Clavien-Dindo >= III were found in 3.8% (0-8.6). Analyzing oncologic outcomes mean follow-up was 26 months (23-31): at one year after HIFU, negative biopsy rate for clinically significant PCa was 87% (79-96), whereas salvage treatment-free survival rate was 92% (85-98). Regarding functional outcomes, reported potency rates were 74% (64-84), and continence 96% (91-100), although definitions of potency and continence were not homogenous across studies. Conclusions: This pooled analysis of the results of focal HIFU treatment of PCa shows promising oncologic and functional outcomes. Well-selected patients may be candidates for such a conservative partial treatment of the gland. Well-designed trials are awaited to compare HIFU focal treatment with current standard of care.