RATIONALE: High-intensity focused ultrasound energy may be able to kill tumor cells by heating them without affecting normal tissue.

PURPOSE: This phase II trial is studying how well high-intensity focused ultrasound ablation therapy works in treating patients with localized prostate cancer.

OBJECTIVES:

Primary

• To determine patient acceptability, feasibility, and side-effect profile by evaluating records of adverse events.
• To determine patient acceptability, feasibility, and side-effect profile by evaluating urinary symptoms and erectile function before study stage 1 (verification), before study stage 2 (treatment), and at each follow-up visit.

Secondary

• To determine the effectiveness of therapy by post-treatment transrectal ultrasound-guided biopsies at 6 months and if there is evidence of biochemical failure.
• To determine the effectiveness of therapy by post-treatment MRI to evaluate area of necrosis and presence of any residual tissue.
• To determine the effectiveness of therapy by measurement of prostate-specific antigen (PSA) at each follow-up visit and measurement of time to PSA nadir.
• To determine the effectiveness of therapy by recording the need for secondary or adjuvant treatment following therapy.

OUTLINE: Patients undergo hemiablation using high-intensity focused ultrasound to the side of the prostate with cancer and up to 5 mm over into the contralateral side to ensure adequacy.

Patients complete questionnaires periodically during study to assess urinary symptoms and erectile dysfunction. These include the International Index of Erectile Function-15 [IIEF-15]; the International Prostate Symptom Score [IPSS] and IPSS-QoL; the Functional Assessment of Cancer Therapy - Prostate (FACT-P); and the Continence Questionnaire.

After completion of study treatment, patients are followed at 2-7 days, 7-14 days, and at 1, 3, 6, 9, and 12 months.

DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the prostate, meeting the following criteria:

  • Gleason score ≤ 7 (patterns 3+4 or 4+3 or less are acceptable)
  • Cancer prostate-confined only
  • Cancer confined to one lobe as defined by transrectal ultrasound (TRUS) biopsy
  • Serum prostate-specific antigen (PSA) ≤ 15 ng/mL
  • Prostate volume ≤ 40 cc OR AP length of prostate < 4 cm

• Unilateral prostate adenocarcinoma must be verified in stage 1 of this trial unless the patient has had multi-sequence MRI and transperineal template biopsies outside of this trial in similar procedure protocols to this trial

• No evidence of metastatic disease

• No intraprostatic calcifications ≥ 10 mm in size in cancer-positive side of prostate

PATIENT CHARACTERISTICS:

• Life expectancy ≥ 5 years
• No latex allergies
• No American Society of Anesthesiology surgical risk score III or IV
• No contraindications to MRI scanning (e.g., severe claustrophobia, permanent cardiac pacemaker, or metallic implant likely to contribute significant artefact to images)
• Must be fit for general anesthesia or regional anesthesia as assessed by the consultant anesthetist

PRIOR CONCURRENT THERAPY:

• More than 6 months since prior androgen suppression therapy
• No prior radiotherapy for prostate cancer
• No prior chemotherapy for prostate cancer
• No prior significant rectal surgery preventing insertion of transrectal probe
• No prior transurethral resection of the prostate or laser prostatectomy
• No prior high-intensity focused ultrasound, cryosurgery, thermal, or microwave therapy to the prostate