Evaluation of Tumor Control Based on Serial Multiparametric MRI and Post-Treatment Biopsies For Patients Treated With Dose Intensification to the Dominant Intra-Prostatic Lesion (DIL) Using Ultra-Hypofractionated, MR-Guided Radiotherapy

Exclusion Criteria

• •1. Gleason score \>7
• •2. PSA \>20 ng/mL
• •3. Prior or concurrent androgen deprivation therapy for prostate cancer
• •4. MRI findings: suspicious for/probable ECE
• •5. MRI findings: \>2 disease foci identifiable
• •6. Evidence of metastatic disease on bone scan or MRI/CT
• •7. MRI ineligibility due to: the presence of a cardiac pacemaker, defibrillator, or other implanted metallic or electronic device which is considered MR unsafe; severe claustrophobia; inability to lie flat for the duration of the study; etc.
• •8. Metallic implant or device in the pelvis that might distort the local magnetic field and compromise quality of mp-MRI
• •9. Lateral pelvic separation greater than 50 cm and/or anterior-posterior separation greater than 35 cm which are incompatible with MR for Calculating ATtenuation (MRCAT) reconstruction
• •10. Contra-indications to receiving gadolinium contrast
• •11. KPS \< 80
• •12. Pelvic or Prostate MRI or CT (MRI preferred) evidence of radiographic T3, T4, or N1 disease
• •13. Prior history of transurethral resection of the prostate
• •14. Prior history of urethral stricture
• •15. Prior history of pelvic irradiation
• •16. History of inflammatory bowel disease
• •17. Unable to give informed consent
• •18. Unable to complete quality of life questionnaires
• •19. Abnormal complete blood count, including any of the following:
• •* Platelet count less than 75,000/ml
• •* Hb level less than 10 gm/dl
• •* White blood cell (WBC) less than 3.5/ml
• •* Abnormal renal function tests (creatinine \> 1.5)