Targeted Focal Cryoablation for Prostate Cancer With Real-time Transrectal Ultrasound-guided Free-hands Technique: A Step-by-step Technique

Objective: For targeted prostate cryoablation, template-grid technique is widely adapted. As long as using template-grid, the angle of cryoprobe placement is limited in 1 direction through grid-hole. Accordingly, the neurovascular bundles are injured by the ice-ball formation outside of the prostate. The free-hands technique allows the ice-ball to cover the entire cancer and preserve neurovascular bundles because of the ideal ice-ball formation within prostate and along with the prostate contour.

Material and methods: Primary localized prostate cancer which has typically single focus of Gleason 7 cancer is targeted, which is MRI-visible targeted-biopsy proven clinically significant cancer. The procedure is performed with real-time transrectal ultrasound-guided free-hands technique. Three cryoprobes are used, including the main probe to target the center of the image-visible lesion, and other 2 probes to cover the safety margins. The entry of the probe into the prostate is achieved in the apex level and then the angle of the insertion is changed laterally to hit the center of the cancer. The ice-ball formation is aiming lethal temperature to cover the entire cancer lesion, with minimizing of the thermal injury in the functional anatomies such as neurovascular bundles and sphincter.

Results: The most technically challenging procedure is to treat the caner lesion in contact with prostate posterior margin. Ice-ball extension needs to extend over 5 mm extraprostate toward the rectal wall, in order to achieve the lethal temperature in contact with posterior prostate capsule. The cryo-prove would be fixed in the prostate tissues completely by freezing-effect. By the lift-up manipulation of the probe anteriorly, we can easily lift the prostate upward, resulting in making of the Denonviellie space wider.

Conclusion: This video provides a step-by-step targeted cryoablation for prostate cancer that can be performed safely and effectively. This approach minimizes the thermal injury in the functional anatomies such as neurovascular bundles and sphincter.