Medium-term outcomes of High-Intensity Focused Ultrasound (HIFU) focal treatment for primary localized prostate cancer: Single-center study

Abstract Background Focal therapy maintains local control of prostate cancer (PCa) while preserving part of the healthy prostate parenchyma in order to limit the functional impact. This study has evaluated the medium-term oncological and functional outcomes of primary focal HIFU therapy in patients with localized prostate cancer. Methods From 2009 to 2019, 256 patients with low- or intermediate-risk PCa (unilateral positive biopsy ISUP grade 1 to 3, ≤cT2b and PSA ≤15ng/ml) were included. Follow-up with regular and MRI was performed. All patients had systematic follow-up biopsies at 1 year and in case of suspected recurrence. Failure was defined by any positive biopsy in the treated area. Univariate and multivariate analyses were performed to identify failure-predictive factors. Urinary continence and erectile function were analyzed. Results The median age was 68.1 years (IQR: 62.3-72.2), and the median follow-up was 5.2 years (IQR: 3.0-7.1). 118 (46.1%) patients were considered in HIFU failure because of positive control biopsy in a treated area, and 66 had clinically significant cancer. 138 patients (53.9%) had local control of PCa after primary HIFU (95 had negative biopsies, and 43 had positive biopsies in non-treated areas). Failure-free survival at 2 and 4 years were 67.3% (95% CI 57.5-76.1) and 53.8% (95% CI 44.8-63.3). No death from PCa was reported. PSA density (PSA-D) (OR: 0.55, 95% CI 0.31-0.97) was found to be an independent predictive factor of focal HIFU failure (p=0.041). The rates of erectile dysfunction and urinary incontinence were 7% and 1.6%. Conclusion Focal HIFU treatment provides satisfactory medium-term disease control in more than half of the patients with limited morbidity. Preoperative PSA density was significantly associated with failure. in the future, patient selection will have to take into account additional parameters if we want to further improve treatment results. Patient summary: We analyzed the medium-term oncological and functional outcomes of primary focal HIFU therapy in patients with localized prostate cancer. The treatment provides a mid-term disease control in more than half of the patients with limited morbidity. More rigorous patient selection, including PSA density, should lead to improved oncologic outcomes of focal HIFU.