Inclusion Criteria:

          1. Provision of signed and dated informed consent form.

          2. Stated willingness to comply with all study procedures and availability for the
             duration of the study.

          3. Male, aged 18 or above.

          4. Histologic proven diagnosis of cancer of the prostate within one year of registration.

          5. Unfavorable-intermediate risk, high risk, or very high-risk prostate cancer as
             determined by the NCCN Guidelines Version 4.2019.

          6. History and physical exam completed up to 6 months before registration.

          7. PSA value < 50 ng/mL prior to androgen deprivation therapy and up to 6 months before
             registration

          8. ECOG performance status 0 or 1.

          9. Pelvic MRI obtained up to 6 months before registration.

        Exclusion Criteria:

          1. Evidence of bone metastases.

          2. Diagnosis of a prior invasive malignancy (except for non-melanoma skin cancer), unless
             the participant has been disease-free for at least 3 years.

          3. Patient has had previous radical surgery (prostatectomy) or cryosurgery for prostate
             cancer.

          4. Patient has had previous pelvic irradiation, prostate brachytherapy, or bilateral
             orchiectomy.

          5. Patient has had prior radiotherapy, including brachytherapy, to the region of this
             study cancer that would result in overlap of radiation therapy fields.

          6. Patient has had previous or concurrent cytotoxic chemotherapy for prostate cancer
             (prior chemotherapy for different cancer is allowed).

          7. Patient has MRI incompatible metallic implant(s) that cannot be removed.

          8. The patient has severe or active co-morbidities as defined by the following:

               -  Unstable angina and/or congestive heart failure requiring hospitalization within
                  6 months (180 days) of registration

               -  Transmural myocardial infarction within 6 months (180 days) of registration

               -  Acute bacterial or fungal infection requiring intravenous antibiotics at the time
                  of registration

               -  Chronic obstructive pulmonary disease exacerbation or other respiratory illness
                  requiring hospitalization or precluding study therapy at the time of registration

               -  Hepatic insufficiency resulting in clinical jaundice and/or coagulation effects
                  or severe liver dysfunction.

               -  Acquired immune deficiency syndrome (AIDS) based upon current CDC definition. The
                  need to exclude patients with AIDS from this protocol is necessary because the
                  treatments involved in this protocol may be slightly immunosuppressive.
                  Protocol-specific requirements may also exclude immuno-compromised patients.