Potential Candidates for Focal Therapy in Prostate Cancer in the Era of Magnetic Resonance Imaging-targeted Biopsy: A Large Multicenter Cohort Study

Abstract

Background: Focal therapy (FT) with its favorable side-effect profile represents an option between active surveillance and traditional whole-gland treatment in localized prostate cancer (PCa). Consensus statements recommend eligibility criteria based on magnetic resonance imaging (MRI)-targeted and systematic combination biopsy.

Objective: To estimate the future potential of FT by analyzing the number of men eligible for FT among all men with biopsy-proven PCa and to judge the potential of different energy sources.

Design, setting, and participants: Consensus criteria on FT were analyzed. Patients with biopsy-proven PCa from six tertiary referral hospitals and one outpatient practice in Germany had received a software-based combination biopsy. Men with Prostate Imaging Reporting and Data System (PI-RADS) ≥3 lesions based on PI-RADS v2 were included.

Outcome measurements and statistical analysis: Patients were analyzed for potential treatment by FT and hemiablation. MRI lesions were mapped according to prostatic zones.

Results and limitations: In total, 2371 patients were analyzed. According to consensus criteria (biopsy-proven unifocal lesion of International Society of Urological Pathology [ISUP] grade group ≤2, prostate-specific antigen [PSA] ≤15ng/mL, and life expectancy >10yr), 303 patients (12.8%; ISUP 1: n=148 [6.2%]; ISUP 2: n=155 [6.5%]) were potential candidates for FT. A maximum PSA level of <10ng/mL would exclude further 60 (2.5%) of these men. The eligibility for hemiablation is slightly higher (16.2%). Unifocal lesions (n=288) were equally distributed within the prostate (anteriorly [31%], apically [29%], and dorsally [36%]).

Conclusions: With adherence to consensus statements, only a minority of PCa patients present as potential candidates for FT. Distribution of tumor localization suggests the need for different energy modalities to warrant an optimal FT treatment.

Patient summary: We analyzed how many men who receive a magnetic resonance imaging-targeted and systematic prostate biopsy are candidates for the experimental focal therapy of the prostate. When following expert recommendations, only a small number of men are potential candidates for this alternative treatment.

Keywords: Biopsy; Consensus; Eligibility criteria; Focal therapy; Focal therapy modalities; Hemiablation; Multiparametric magnetic resonance imaging; Partial gland ablation; Patient selection; Prostate neoplasms.