Inclusion Criteria:

          -  Confirmed diagnosis of prostate adenocarcinoma after radical prostatectomy (primary
             small cell carcinoma of the prostate is not allowed, however adenocarcinoma with
             neuroendocrine differentiation is allowed)

          -  Presence of 1-5 visible metastases (by PSMA PET-CT)

               -  At least one metastasis must be M1a-b

               -  Visceral metastases are not allowed

               -  Patients may have any number of pelvic nodal metastases (but largest must be < 2
                  cm)

               -  Metastases must be amenable to treatment with SBRT

               -  Biopsy of one metastasis must be attempted, unless unsafe to perform

          -  Patient must be fit to undergo SBRT to all visible sites of metastases, ADT

          -  Total testosterone > 150 ng/dL prior to ADT (optimal time to measure total
             testosterone is between 8 and 9 am)

          -  Adequate performance status (Eastern Cooperative Oncology Group [ECOG] 0-1)

          -  Hemoglobin >= 9.0 g/dL, independent of transfusion and/or growth factors within 3
             months prior to randomization

          -  Platelet count >= 100,000 x 10^9/uL independent of transfusion and/or growth factors
             within 3 months prior to randomization

          -  Serum albumin >= 3.0 g/dL

          -  Glomerular filtration rate (GFR) >= 45 mL/min

          -  Serum potassium >= 3.5 mmol/L

          -  Serum total bilirubin =< 1.5 x upper limits of normal (ULN)

               -  Note: In subjects with Gilbert?s syndrome, if total bilirubin is > 1.5 x ULN,
                  measure direct and indirect bilirubin and if direct bilirubin is =< 1.5 x ULN,
                  subject may be eligible

          -  Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) < 2.5 x ULN

          -  Medications known to lower the seizure threshold must be discontinued or substituted
             at least 4 weeks prior to study entry

        Exclusion Criteria:

          -  Any evidence of spinal cord compression (radiological or clinical)

          -  Prior pelvic malignancy

          -  Prior pelvic radiation aside from salvage prostate radiation

          -  Concurrent malignancy aside from superficial skin cancers or superficial bladder
             tumors

          -  Inability to undergo radiotherapy, or ADT

          -  Primary small cell carcinoma of the prostate (prostate adenocarcinoma with
             neuroendocrine differentiation is allowed)

          -  Inflammatory bowel disease or active collagen vascular disease

          -  History of any of the following:

               -  Seizure or known condition that may pre-dispose to seizure (e.g. prior stroke
                  within 1 year to randomization, brain arteriovenous malformation, Schwannoma,
                  meningioma, or other benign central nervous system [CNS] or meningeal disease
                  which may require treatment with surgery or radiation therapy)

               -  Severe or unstable angina, myocardial infarction, symptomatic congestive heart
                  failure, arterial or venous thromboembolic events (eg, pulmonary embolism,
                  cerebrovascular accident including transient ischemic attacks), or clinically
                  significant ventricular arrhythmias within 6 months prior to randomization

          -  Current evidence of any of the following:

               -  Uncontrolled hypertension

               -  Gastrointestinal disorder affecting absorption

               -  Active infection (eg, human immunodeficiency virus [HIV] or viral hepatitis)

               -  Any chronic medical condition requiring a higher dose of corticosteroid than 10
                  mg prednisone/prednisolone once daily

               -  Any condition that in the opinion of the investigator would preclude
                  participation in this study

               -  Concomitant strong CYP3A4 inducers. (If a strong CYP3A4 inducer must be
                  co-administered, abiraterone acetate dose frequency will be adjusted). [SAFETY:
                  Warning against use with CYP2C8 inhibitors with narrow therapeutic index is also
                  pertinent to be included as it is also part of United States Prescribing
                  Information (USPI): In a CYP2C8 drug-drug interaction trial in healthy subjects,
                  the area under curve (AUC) of pioglitazone (CYP2C8 substrate) was increased by
                  46% when pioglitazone was given together with a single dose of 1,000 mg
                  abiraterone acetate. Therefore, patients should be monitored closely for signs of
                  toxicity related to a CYP2C8 substrate with a narrow therapeutic index if used
                  concomitantly with ZYTIGA]

               -  Treatment with CYP2D6 substrates that have a narrow therapeutic index. If an
                  alternative treatment cannot be used, a dose reduction of the CYP2D6 substrate
                  may be considered

               -  Baseline moderate and severe hepatic impairment (ChildPugh Class B & C)

          -  Presence of visceral metastases (i.e., stage M1c)