Tumor-Targeted Radiotherapy for Localized Prostate Cancer

Study start date: November 23, 2012

Inclusion Criteria \[applicable to both Cohorts 1 (control) and Cohort 2 (Experimental) unless otherwise specified\]: 1. Histological evidence of prostate adenocarcinoma. 2. Discrete intra-prostatic tumor that can be confidently visualized on MRI prior to radiotherapy (\>5mm maximum diameter but \<33% of prostate volume, biopsy confirmed from initial diagnosis or interventional Biopsy) ) 3. At least 18 years old 4. ECOG performance status 0 or 1 5. Informed consent: All patients must sign a document of informed consent indicating their understanding of the investigational nature and risks of the study before any protocol related studies are performed (this does not include standard care laboratory tests or imaging studies). 6. Patients will be one of the following risk groups prior to therapy: * Low-risk disease (Gleason 6 and PSA \<10 and T1) AND \>50% of biopsy cores involved with tumor * Intermediate-risk disease (Gleason 7 or PSA 10-20 or T2) * High-risk disease (Gleason \>8 or T3 or PSA \>20) 7. Risk of LN involvement \<30% (Roach formula = 2/3PSA(\[G-6\]x10)) 8. Patients who received 78Gy RT to the prostate gland 3-4.5 years prior to enrollment (Cohort 1 only) Exclusion Criteria \[applicable to both Cohorts 1 (control) and Cohort 2(Experimental) unless otherwise specified\]: 1. Previous history of radiation therapy to the prostate (Cohort 2) 2. Diagnosis of another cancer not being skin cancer within the last 5 years (Cohort 2) 3. Patients weight as per MRI Technologist's discretion 4. Patients with contraindications to MRI: this includes patients with pacemakers, cerebral aneurysm clips, shrapnel injury or implantable electronic devices not compatible with MRI determination. Exceptions will be allowed if deemed sage and appropriate by the MRI technologist. 5. Severe claustrophobia 6. Bleeding diathesis and anti-coagulative therapy that cannot be temporarily ceased precluding biopsy 7. Current hormonal therapy (Cohort 1) or initiated \>2 weeks prior to enrollment (Cohort 2) 8. Radiological evidence of regional or distant metastases (Cohort 2) 9. Other urinary or medical conditions deemed by the PI or associates to make the patient ineligible for MRI-guided prostate biopsy 10. Contraindications to the endorectal coil, surgically absent rectum, severe hemorrhoids or previous colorectal surgery 11. Contraindications to conscious sedation 12. Latex allergy 13. History of Ulcerative Colitis, Crohn's Disease, Ataxia Telangiectasia, or SLE (Cohort 2) 14. Other medical conditions deemed by the PI to make patient ineligible for study intervention