Prospective Multicenter Phase II Study on Focal Therapy (Hemiablation) of the Prostate with High Intensity Focused Ultrasound

Abstract

Purpose: We evaluated focal therapy with high intensity focused ultrasound hemiablation in a prospective trial.

Materials and methods: We performed a prospective, multicenter, single arm study in patients with unilateral low/intermediate risk prostate cancer who were treated from April 2013 through March 2016 in Germany in AUO (Arbeitsgemeinschaft Urologische Onkologie) Study Protocol AP 68/11. Unilateral prostate cancer was assessed by transrectal ultrasound guided biopsy and multiparametric magnetic resonance imaging. Hemiablation was done using the Ablatherm® or the Focal One® device. The oncologic outcome was assessed by the salvage treatment rate, multiparametric magnetic resonance imaging and rebiopsy at 12 months. Functional outcome, quality of life, anxiety and depression were measured by validated questionnaires at baseline and every 3 months.

Results: Of the 54 recruited patients 51 completed 12-month or greater visits. Mean ± SD followup was 17.4 ± 4.5 months. Mean prostate specific antigen decreased from 6.2 ± 2.0 to 2.9 ± 1.9 ng/ml at 12 months (p <0.001). Biopsy at 12 months was positive for any prostate cancer and for clinically significant prostate cancer in 13 (26.5%) and 4 (8.2%) of the 49 patients, respectively. Posttreatment multiparametric magnetic resonance imaging had limited 25% sensitivity for clinically significant prostate cancer. Ten patients (19.6%) underwent salvage treatment. Potency was maintained in 21 of the 30 men who were potent preoperatively. There was no increase in incontinence. Quality of life, anxiety and depression did not change postoperatively. The study was limited by a short followup and the lack of a control arm.

Conclusions: Focal therapy hemiablation is safe with little alteration of functional outcome. The oncologic outcome is acceptable on short-term followup. Followup multiparametric magnetic resonance imaging performed poorly and should not replace repeat biopsy. Focal therapy has no impact on posttreatment anxiety and depression.

Keywords: high-intensity focused ultrasound ablation; magnetic resonance imaging; prostatic neoplasms; quality of life; surveys and questionnaires.