The purpose of this research is to gather information on the safety and effectiveness of using an imaging technique called magnetic resonance imaging (MRI) to decrease radiation dose to the uninvolved prostate (areas of the prostate that do not clearly have cancer cells) while increasing radiation dose to the nodules (hardened areas of the prostate that have cancer cells).

Inclusion Criteria:

• Adult (≥ 18 years old) male patients with an ECOG Performance Status 0-2
• Histologically-confirmed, MRI-visible prostate adenocarcinoma with NCCN intermediate- or high-risk disease1 without extra-pelvic metastasis.

Exclusion Criteria:

• Distant metastases
• Prior active treatment for prostate cancer including radical prostatectomy, high-intensity focused ultrasound (HIFU), cryosurgery, ADT, or cytotoxic chemotherapy for treatment of prostate cancer. Patients with prostate cancer on active surveillance prior to the study are not excluded if they have not received active treatment.
• Prior pelvic radiotherapy including brachytherapy.
• Additional active concurrent malignancies (except localized cutaneous squamous or basal cell carcinomas).
• Comorbid conditions that, in the opinion of the treating radiation oncologist, preclude the patient from safely receiving the protocol-specified treatment including RT and/or ADT.
• Patients with contraindications to MRI including patients with ferromagnetic materials in their body (e.g. bioimplants, surgical hardware, shrapnel), patients who are unable to receive contrast due to history of allergy or impaired renal function (glomerular filtration rate < 30 mil/min), and patients unable to tolerate MRI for other reasons (e.g. significant claustrophobia).
• Patients for whom hydrogel or hyaluronic acid spacer will be placed.
• Patients incapable of giving informed consent.
• Patients who are unable to adhere to the experimental protocols for any reason.

The study will be limited to male patients given that prostate cancer does not occur in females.