Prostate cancer treatment by the latest focal HIFU device with MRI/TRUS-fusion control biopsies: A prospective evaluation.

ABSTRACT

OBJECTIVES: Magnetic resonance imaging/transrectal ultrasound (MRI/TRUS) fusion-guided focal high intensity focused ultrasound (HIFU) therapy of the prostate has recently been developed as a selective HIFU-therapy technique to enable targeted ablation of prostate cancer. Here we report a series of patients treated with focal HIFU therapy, discuss its potential pitfalls, and address controversies concerning the indications. MATERIALS AND METHODS: This single-center prospective study reports outcomes of patients treated from September 2014 to March 2016. Follow-up was a minimum of 12 months. MRI/TRUS-fusion-guided HIFU was performed under general anesthesia using the Focal One® device (EDAP, France). A control biopsy at 12 months was taken using the MRI/TRUS-fusion biopsy platform Artemis™ (Eigen, California) combining targeted and systematic cores. Prostate-specific antigen (PSA) changes from baseline, patient-reported outcome measures, and complications using the Clavien-Dindo classification system are also reported. RESULTS: Twenty-four patients (PSA < 10 ng/ml, n = 17 Gleason 3+3, n = 7 Gleason 3+4) with either unifocal or bifocal prostate imaging reporting and data system (PI-RADS) 3-5 lesions (n = 19) or without a PI-RADS lesion (n = 5) were treated. Nineteen patients underwent focal HIFU, five patients zonal HIFU. Of the 20 patients that had biopsies at 12 months, 8 patients had a positive biopsy within the ablation zone (overall cancer free rate 60%). Using different definitions of clinically significant cancer, the cancer-free rate for the ablation zone varies between 75% and 95%. Four of the eight patients (all persistent Gleason 3+4 or upgrading to 4+3) underwent a radical whole gland salvage therapy. Patient-reported outcome measures showed no significant decrease in urinary continence (expanded prostate cancer index composite -26 urinary incontinence P = 0.080), but there was a reduction in potency (International index of erectile function in preoperatively potent patients median decrease of 2 points to a median of 19 points at 12 months; 95% confidence interval 15.79-22.21; P = 0.044). Only one complication > grade II occurred. CONCLUSIONS: Targeted MRI/TRUS fusion-guided focal HIFU allows local tumor ablation, but is not free from limitations. The procedure has good functional outcomes and a quick recovery. Multicenter trials with more patients are required to determine the procedure´s role in the prostate cancer therapy algorithm.