The purpose of this study is to determine the substantial equivalence of the Ablatherm high intensity focused ultrasound (HIFU) as compared to cryotherapy for the treatment of low risk, localized prostate cancer.

Primary hypothesis of this clinical investigation is that HIFU with the Ablatherm Integrated Imaging is non-inferior to minimally invasive cryosurgery as an effective treatment method for low risk, localized prostate cancer.

Inclusion Criteria:

• Diagnosis of prostate cancer confirmed by PSA and prostate biopsy
• Male subjects, aged equal to or over 50 years
• Organ-confined prostate cancer, clinical stage T1a, b, or c or T2a
• At least one positive biopsy within the previous 6 months
• PSA equal to or less than 10 ng/ml
• Gleason score equal to or less than 6
• Histological grading of 3+3, 3+2, 2+3, 2+4, or 2+2 based upon the baseline transrectal ultrasound (TRUS)-guided 10 core biopsy results. A subject with a histological grading of primary 4 will not be permitted for study enrollment.
• Prostate volume equal to or less than 40 cc
• Prostate anteroposterior (AP) diameter equal to or less than 25 mm
• Normal rectal anatomy and rectal mucosa
• Maximum rectal wall measurement 6 mm
• The Investigator has completed a medical history and a physical examination to assure that the subjects meet all study enrollment criteria
• The subject is willing and able to read, understand, and sign the study specific informed consent form
• The subject agrees to comply with study protocol requirements, including HIFU or cryotherapy treatment and all follow up visit requirements through 24 months of follow up treatment.

Exclusion Criteria:

• Evidence of seminal vesicle involvement
• Evidence of lymph node involvement or metastasis
• Any previous treatment for prostate cancer including: external beam radiation therapy (EBRT), hormone therapy and/or previous bilateral orchiectomy
• Previous surgery or procedure of the prostate (except prostate biopsy) or urethra within the prior one year
• Calcification inducing a shadow in the prostate which cannot be included in the targeted volume
• Large median lobe of the prostate which cannot be included in the target volume
• Use within the previous 2 months of finasteride
• Previous rectal surgery (other than hemorrhoidectomy) or history of rectal disease
• Active inflammatory bowel syndrome
• Current superficial bladder cancer, urethral stricture, or bladder neck contracture
• Active urinary tract infection or prostatitis (the subject may be enrolled once the infection has been treated and has resolved)
• Compromised renal function or upper urinary tract disease as a result of urinary obstruction
• A history of bleeding disorders/coagulopathy or ongoing treatment for this condition
• Urinary tract or rectal fistula
• Rectal fibrosis, rectal stenosis, or other anomalies making the Ablatherm Integrated Imaging rectal probe insertion difficult
• Anatomical anomaly of the rectum or anomaly of the rectal mucous membrane
• Prostate seroma, prostate abscess, or urethral stenosis
• An intraprostatic implant such as a stent or catheter, or any implant or prosthesis at less than 1 cm from the prostate
• Interest in future fertility
• Concurrent illness, disability, or geographical residence would hamper attendance at required study visits
• Known latex hypersensitivity
• Current participation in another clinical investigation of a medical device or a drug or has participated in such a study within 30 days prior to study enrollment
• The Investigator believes that the subject will be unwilling or unable to comply with study protocol requirements, including the HIFU or cryotherapy procedure and study-related follow up visit requirements.