Prospective trial of regional (hockey-stick) prostate cryoablation: oncologic and quality of life outcomes.

Purpose: To report long-term follow-up of the efficacy of subtotal prostate ablation using a "hockey-stick" template, including oncologic control and quality of life (QoL) impact.

Methods: We performed a prospective controlled trial to evaluate the efficacy of subtotal prostate ablation in selected men with baseline and confirmatory biopsy showing grade group (GG) 1-2 prostate cancer. "Hockey-stick" cryoablation that included the ipsilateral hemi-gland and contralateral anterior prostate was performed. Prostate biopsies and QOL queries were performed at 6, 18 and 36 months following regional ablation, and follow-up was updated to include subsequent clinic visits.

Results: Between August 2009 and January 2012, 72 men were screened for eligibility and 47 opted to undergo confirmatory biopsy. Of these, 23 were deemed eligible and treated with regional cryoablation. Median age was 64 years. Median follow-up was 74 months. A single patient had < 1 mm of in-field viable tumor with therapy effect on 36-month biopsy. At time of last follow-up, a total of 12/23 (52%) patients did not have evidence of disease, all patients had preserved urinary control with no patients requiring pads for urinary incontinence. Sexual decline was significant at 3 and 6 months (P < 0.01 for both), though improvement was seen at subsequent time points.

Conclusion: Subtotal (hockey-stick template) cryoablation of the prostate provides oncologic control to targeted tissue in a generally low-risk group with minimal impact on sexual and urinary function. Further studies are needed to evaluate this ablation template in the MRI-targeted era and higher risk populations.