Real-time transrectal ultrasonography-guided hands-free technique for focal cryoablation of the prostate.

Abstract

To describe, step-by-step, our hands-free technique for focal cryoablation of prostate cancer. After detailed discussion of its limitations and benefits, consent was obtained to perform focal cryoablation in patients with biopsy-proven unilateral low- to intermediate-risk prostate cancer. The procedure was performed transperineally, using a hands-free technique (without an external grid template) under real-time bi-plane transrectal ultrasonography (TRUS) guidance, using an argon/helium-gas-based third generation cryoablation system. Follow-up consisted of validated questionnaires, physical examination, PSA measures, multiparametric TRUS and/or magnetic resonance imaging (MRI) and mandatory biopsy. The important steps for achieving safety, satisfactory oncological and functional outcomes included: patient selection, including TRUS/MRI fusion target biopsy; thermocouple and cryoprobe placement with a hands-free technique, allowing delivery in unrestricted angulations according to the prostatic contour, the course of the neurovascular bundle and the rectal wall angle; and hands-free bi-plane TRUS probe manipulation to facilitate real-time monitoring of anatomical landmarks at the ideal angle of the image plane. To achieve a lethal temperature in the known cancer area, while preserving the urinary sphincter, neurovascular bundle, urethra and rectal wall, continuous intraoperative control of the thermocouple temperatures was necessary, as were real-time TRUS monitoring of ice-ball size, control of the energy delivered and the use of a warming urethral catheter. We have described step-by-step the focal cryoablation of prostate cancer using a hands-free technique. This technique facilitates the effective delivery of cryoprobes and the intra-operative real-time quick manipulation of the TRUS probe.