Inclusion Criteria:

- Clinical characteristics:

- Stage T1c or T2a

- Prostate-specific antigen (PSA) < 15 ng/ml or PSA density (PSA divided by
prostate volume in cubic centimeters) < 0.15 ng/ml^3

- No evidence of metastatic disease based on National Comprehensive Cancer Network
(NCCN) guidelines:

- Bone scan if PSA > 20 ng/ml and clinical stage T1c

- Bone scan if PSA > 10 ng/ml and clinical stage T2

- Biopsy requirements:

- Gleason score 7 or less

- 25% or fewer biopsies with cancer

- At least 12 biopsy cores of the prostate

- Within 12 months of treatment

- Imaging requirements:

- Up to 2 visible magnetic resonance (MR) lesion(s) concordant with sextant of
biopsy-detected cancer(s)

- MRI within 6 months of treatment

- Karnofsky performance status of at least 70

- General health is suitable to undergo the planned minimally invasive procedures

- Risks, benefits, and alternatives discussed with informed consent given

Exclusion Criteria:

- Previous treatment of prostate cancer with luteinizing hormone releasing hormone
(LHRH) agonist/antagonist, chemotherapy, surgery, or radiation

- Presence of 3 or more visible lesions on MRI

- High suspicion of seminal vesicle invasion or lymph node metastases on MRI

- Unable to tolerate MRI (medical device, foreign body, claustrophobia, body habitus,
or other)

- Renal insufficiency with estimated glomerular filtration rate (eGFR) < 30 ml/min/body
surface area (BSA) based on Modification in Diet Renal Disease equation; inability to
safely receive gadolinium contrast for MRI

- History of prior pelvic surgery with surgical clips remaining in situ (e.g., bladder,
bowel, internal pelvic organs) that compromise MRI image quality

- Other serious illnesses involving the cardiac, respiratory, central nervous system
(CNS), 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