Inclusion Criteria

1. Male subjects age 50 and older.
2. Biopsy proven adenocarcinoma of the prostate (using a IMAGE-guided 14+ core mapping biopsy), and targeted cores as needed obtained up to 6 months prior to scheduled treatment.
3. Patient with intermediate risk, early-stage organ-confined prostate cancer (T1a up to T2b, N0, M0) and voluntarily chooses ExAblate thermal ablation as the non-invasive treatment, who may currently be on watchful waiting or active surveillance and not in need of imminent radical therapy.
4. Patient with PSA less than or equal to 20 ng/mL
5. Gleason score 7 (4 + 3 or 3 + 4), based on mapping prostate biopsy, with no more than 15mm cancer in maximal linear dimension in any single core.
6. Single hemilateral index Gleason 7 lesion, identified in the prostate based on biopsy mapping with supporting MRI; may have secondary Gleason 6 lesion on ipsilateral or contralateral side confirmed with biopsy and/or MRI.
7. Gleason 7 tumors must be MRI visible:
   1. In the event that a tumor is in contact with the capsule, the length of the contact should be ≤ 5 mm, on axial images.
   2. Largest imaging dimension of cancerous finding < 20-mm
8. No definite evidence of extracapsular extension or seminal invasion by MRI
9. Patient should be eligible for both spinal/epidural anesthesia (planned procedure), and general anesthesia (in case of complication, requiring intervention).
10. Patient is willing and able to give consent attend all study visits and complete all questionnaires as defined in the protocol
11. Tumor distance, including tumor free margins, should not be more than 40mm from the rectal wall.

Exclusion Criteria

1. ASA status > 2
2. Contraindications to MRI 2.1 Claustrophobia 2.2 Implanted ferromagnetic materials or foreign objects 2.3 Known intolerance to the MRI contrast agent
3. Severely abnormal coagulation (INR>1.5)
4. Patients with unstable cardiac status including:
   1. Unstable angina pectoris on medication
   2. Patients with documented myocardial infarction within 40 days prior to enrollment
   3. Congestive heart failure NYHA class IV
   4. Patients with unstable arrhythmia status, already on anti-arrhythmic drugs
5. Severe hypertension (diastolic BP > 100 on medication)
6. Severe cerebrovascular disease (multiple CVA or CVA within 6 months)
7. History of orchiectomy, PCa-specific chemotherapy, brachytherapy, cryotherapy, Photodynamic therapy or radical prostatectomy for treatment of prostate cancer; any prior radiation therapy to the pelvis for prostate cancer or any other malignancy.
8. Patient under medications that can affect PSA for the last 3 months prior to MRgFUS treatment (Androgen Deprivation Treatment; alpha reductase inhibitors)
9. Patients with lesions of Gleason 7 or greater outside the planned treatment area.
10. Individuals who are not able or willing to tolerate the required prolonged stationary supine position during treatment (approximately 3 hrs. sonication time)
11. Any rectal pathology, anomaly or previous treatment, which could change acoustic properties of rectal wall or prevent safe probe insertion (e.g., stenosis, fibrosis, inflammatory bowel disease, etc).
12. Any spinal pathology which can prevent safe administration of epidural/ spinal anesthesia
13. Identified calcification of 2 mm or more in largest diameter neighboring the rectal wall (in a distance of less than 5 mm) and interfering with the acoustic beam path.
14. Lower limb musculoskeletal fixed deformities preventing probe insertion or patient positioning during procedure.
15. Prostate with multiple cystic lesions.
16. Evidence of distant prostate cancer, i.e., including lymph nodes and/or metastasis of cancer on imaging
17. Bladder cancer
18. Urethral stricture/bladder neck contracture
19. Active UTI
20. Prostatitis NIH categories I, II and III.
21. Compromised renal function
22. Implant near (<1 cm) the prostate
23. Interest in future fertility
24. 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.