Novel Automated Three-Dimensional Surgical Planning Tool and Magnetic Resonance Imaging/Ultrasound Fusion Technology to Perform Nanoparticle Ablation and Cryoablation of the Prostate for Focal Therapy.

Purpose: Although MRI/ultrasound fusion has been primarily used to assist in the diagnosis of prostate cancer, this technology can also be used to focally treat localized prostate cancer. We present one case of nanoparticle-directed ablation and two cases of cryoablation to focally treat prostate tumors. Patients and Methods: Three patients underwent MRI/ultrasound fusion transperineal prostate biopsies to confirm low- to intermediate-risk prostate cancer. The MRI lesions correlated with the biopsy-proven disease. Pelvic MRI segmentation was performed with DynaCAD 5.0 workstation. The MRI lesion including a 6 to 10 mm margin, prostate, bladder, urethra, urethral sphincter, rectum, and pubic bone were segmented. MRI/ultrasound fusion was performed with the novel Philips UroNav 4.0 system. Lesions were treated with focal nanoparticle ablation or focal cryoablation. Results: A 69-year-old man with a right posterior medial peripheral zone lesion positive for Gleason grade group (GG)3 cancer was treated with focal nanoparticle ablation. The UroNav 4.0 system reported 100% ablation of the segmented tumor and 94% of the 6 to 10 mm margin at the end of the case. A 68-year-old man with a left anterior fibromuscular stroma lesion positive for Gleason GG2 cancer and a 71-year-old man with a right peripheral zone posterior lateral lesion positive for Gleason GG1 cancer were treated with focal cryoablation. The UroNav 4.0 system reported 100% ablation of the segmented tumor and 82% of the 6 to 10 mm margin at the end of the case. Conclusion: Observation of the prostate tumor(s), surrounding critical structures, and pelvis in three dimensions (3D), along with the anticipated ablation zone, is one of the challenges of pelvic surgery and percutaneous ablation. The DynaCAD 5.0 Urology system can create an auto-segmented 3D rendering of critical structures and the tumor(s), as well as observation and quantification of the anticipated ablation coverage, to facilitate preoperative planning of needle placement. ClinicalTrials.gov nos.: NCT02680535 and NCT04656678.