-  INCLUSION CRITERIA:

        Subjects must have prostate cancer, amenable for ultrasound ablation defined as following:

          -  diagnosed by prostate biopsies consist of transrectal ultrasound-guided standard 12
             core biopsy and biopsies of one or two MRI target lesions;

          -  Gleason Score <= 7;

          -  <= 4 cores positive in a standard 12 core biopsy and <= 4 cores positive on MRI target
             lesions biopsy where 2 cores are taken from each of the one or two MRI target lesions;

          -  histologically positive standard biopsy cores must be from the same location in the
             prostate as an MRI target lesion(s) and reviewed by NCI urologic pathologist. (Left /
             Right, Base, Mid-Gland, Apex).

          -  organ confined clinical T1c or clinical T2a prostate cancer that is visualized on MRI
             imaging. Note: Participants after prostate cancer treatment with local recurrence or
             residual tumor which is visible on MRI are eligible.

          -  PSA < 20 ng/ml.

          -  Adults (>= 18 years of age)

          -  Participants must have adequate organ and marrow function as defined below:

        Platelets >= 50,000/mcL

        Hemoglobin >= 8 g/dL

        ALT or AST <= 5 x ULN

        Measured or calculated creatinine clearance (CrCl) (eGFR may also be used in place of
        CrCl)* >= 30 mL/min/1.73 m^2

        ALT (SGPT)=alanine aminotransferase (serum glutamic pyruvic transaminase); AST
        (SGOT)=aspartate aminotransferase (serum glutamic oxaloacetic transaminase); GFR=glomerular
        filtration rate; ULN=upper limit of normal.

        *Creatinine clearance (CrCl) or eGFR should be calculated per institutional standard.

        - Subjects must be able to understand and willing to sign a written informed consent
        document.

        EXCLUSION CRITERIA:

          -  The presence of 3 or more MRI visible lesions positive for prostate cancer on biopsy

          -  Targeted lesion ablation length from apex to base of >5 cm or lesion extending >3 cm
             from the urethra.

          -  Target ablative volume of greater than 100 ml.

          -  Presence of calcifications that would impede ultrasound transmission between the
             urethra and ablative target.

          -  The participant is unable to tolerate MRI (foreign body, i.e., pacemaker or other
             implanted device; claustrophobia; inability to tolerate rectal coil; etc.)

          -  The participant with the inability to follow up

          -  Acute urinary tract infection

          -  Lower urinary tract symptoms defined by an IPSS > 20

          -  Participants with uncontrolled coagulopathies (including liver dysfunction, or
             untreated hereditary coagulopathies which have a standard of care treatment) per
             surgeon discretion based on bleeding risk.

          -  Other serious illnesses according to the PI: involving the cardiac, respiratory, CNS,
             renal, or hepatic organ systems, which would preclude study completion or impede the
             determination of causality of any complications experienced during the conduct of this
             study.