• Attainment achievement of prostate-specific antigen (PSA) nadir < 0.5 ng/ml and stability of PSA according to American Society for Therapeutic Radiology and Oncology (ASTRO) criteria through 24 month follow up without a positive biopsy
  

• Achievement of a nadir PSA within 6 months < 0.5 ng/ml
  
• Overall survival, defined as time to death due to any cause
  
• Disease specific survival, defined as the time to death due to the underlying disease
  
• Change from baseline in the University of California, Los Angeles Quality of Life (UCLA QOL)
  
• Change from baseline in the International Prostate Symptom Score (IPSS)
  

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 60 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, or other agents (e.g. saw palmetto) that affect PSA levels
• 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.