Water Vapor Ablation for Grade Group 3 Prostate Cancer

The goal of this study is to evaluate the safety and effectiveness of the Vanquish Water Vapor Ablation System ("Vanquish") in participants with Grade Group 3 (GG3) intermediate-risk prostate cancer. Participants will undergo therapy with the Vanquish System and complete follow up visits at 7 days, 6 weeks, 6 months, 12 months, 18 months, and 24 months.

Inclusion Criteria: * Participant has been diagnosed with Grade Group 3 (GG3) intermediate-risk prostate cancer. * ≤20 ng/ml prostate specific antigen (PSA). * Prostate volume of 20-80cc per Central Imaging read. * ≥50 years of age; with life expectancy of ≥10 years. * Clinical cancer stage less than or equal to T2c (tumor may involve both sides of the prostate but without evidence that tumor extends outside of the prostate and with no cancer cells found in nearby lymph nodes) evaluated by prostate specific membrane antigen positron emission tomography (PSMA PET) scan. * Within 6 months prior to signing consent have had a multiparametric MRI (mpMRI). a.) mpMRI results must show localized disease meaning a single MRI region of suspicion (PI-RADS lesion volume ≤2.25cc with a maximum lesion diameter \