Salvage radical prostatectomy after failed transperineal cryotherapy: histologic findings from prostate whole-mount specimens correlated with intraoperative transrectal ultrasound images

Abstract

Objectives This study evaluates the potential for salvage radical prostatectomy after failure of transrectal ultrasound (TRUS)-guided percutaneous cryosurgical ablation of the prostate. An additional purpose was to determine the accuracy of intraoperative TRUS to delineate the extent of freeze destruction that results from cryosurgery. Methods Six patients with biopsy-confirmed, Stage T3 prostate cancer underwent salvage radical prostatectomy 3 to 10 months after failing prostate cryosurgery. Zones of freeze destruction (resolving coagulative necrosis) and residual adenocarcinoma were mapped on the coverslips of whole-mount sections. Histologically proven zones of freeze destruction correlating to successfully treated prostatic tissue were compared to the hypoechoic ice ball treatment zones seen on intraoperative TRUS images. Results The whole mounts were found to contain necrotic areas of cryodestruction that appeared much smaller than predicted by intraoperative ultrasound. Each of the cases also contained residual viable adenocarcinoma. All patients are alive and clinically free of localized disease 0.5 to 12 months after salvage radical prostatectomy. Conclusions Salvage radical prostatectomy offers an effective treatment option in patients who have failed transperineal cryosurgery of the prostate. Intraoperative TRUS predicted that the entire prostate would show freeze destruction. Whole-mount analysis, however, revealed areas of remaining unaffected adenocarcinoma and normal prostatic parenchyma. TRUS, therefore, overestimates the area of prostatic tissue destroyed by extreme cold. This finding challenges the assumption that the entire prostate is lethally frozen when its boundaries are included within the hypoechoic ice ball witnessed on TRUS.