High-Intensity Focused Ultrasound Ablation in Treating Patients With Localized Prostate Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed adenocarcinoma of the prostate * Low-risk disease, as defined by the following criteria: * Gleason grade total ≤ 7 (patterns 3+4 or 4+3 or less acceptable) * Localized disease (unilateral or bilateral) (stage T2c, N0, M0 or less) * Serum PSA ≤ 15 ng/mL * Prostate volume ≤ 40 cc or maximum anterior-posterior length ≤ 40 mm * Multi-sequence-MRI and transperineal template 5 mm-spaced biopsies performed within the past 6 months * All malignant areas must be treatable by focal ablation so that approximately 50% of prostate tissue is destroyed and ≥ 1 neurovascular bundle is preserved * No intraprostatic calcifications making high-intensity focused ultrasound of focal areas of cancer untreatable * No metastatic disease PATIENT CHARACTERISTICS: * Life expectancy ≥ 5 years * Must be fit for general or regional anesthesia as assessed by Consultant Anesthetist * No prior rectal fistula * No American Society of Anesthesiology grades III-IV * No latex allergies * No contraindication to MRI scanning (e.g., severe claustrophobia, permanent cardiac pacemaker, or metallic implant likely to contribute significant artifact to images) * No moderate to severe inflammatory bowel disease PRIOR CONCURRENT THERAPY: * No androgen suppression treatment within the past 6 months * No transurethral resection of the prostate or laser prostatectomy within the past 5 years * No prior treatment (i.e., radiotherapy, brachytherapy, surgery, laser therapy, chemotherapy, high-intensity focused ultrasound, cryosurgery, thermal therapy, or microwave therapy) for prostate cancer * No prior significant rectal surgery preventing insertion of transrectal probe