Inclusion Criteria:

          -  Documented informed consent of participant and/or legally authorized representative

          -  Agreement to provide archival primary or metastatic tumor tissue if available

          -  Eastern Cooperative Oncology Group (ECOG) =< 2

          -  Life expectancy > 12 months

          -  Histologic diagnosis of prostate adenocarcinoma

             * Pure small cell carcinoma will be excluded; however, component of neuroendocrine
             /small cell differentiation will be allowed provided that adenocarcinoma constitutes
             majority of the tissue specimen

          -  Stage M1

             * Metastatic disease can be documented by bone scan or computed tomography (CT) scan
             or magnetic resonance imaging (MRI) or positron emission tomography (PET)/CT or the
             combination of these tests

          -  Up to 4 metastatic lesions:

               -  Must have at least 1 bone lesion AND each non-visceral lesion should be less than
                  5 cm

               -  Visceral lesions will be limited to one lung lesion (< 2 cm) or one lymph node;
                  no liver lesions allowed; lymph nodes allowed provided they are not in a field of
                  prior radiation, and if amenable to SBRT (to be reviewed by principal
                  investigator [PI])

          -  Two lesions can be in close proximity (i.e. within 5 cm of each other) if they meet
             radiation SBRT normal tissue toxicity requirements

          -  If have untreated primary prostate cancer: must undergo debulking prostatectomy

          -  If had prior definitive radiation therapy to the prostate: no evidence of locally
             persistent or recurrent prostate cancer on digital rectal exam (DRE) and imaging
             studies (CT or MRI); retreatment to local residual-recurrent disease will result in
             potential eligibility to be reviewed by PI on a case-by-case basis

          -  Does not have castration resistant disease

             * Castration resistance defined as progression of disease despite serum testosterone
             level of < 50 ng/dL

          -  PSA >= 0.2 prior to start of androgen deprivation treatment

          -  Initiated 28 (+ 7) days of androgen deprivation therapy (ADT) prior to day 1 of
             protocol therapy

             * Only luteinizing hormone-releasing hormone (LHRH) agonist/antagonist treatment is
             considered ADT, bicalutamide or other antiandrogens used alone do not count

          -  May have received prior hormonal therapy in the context of definitive treatment of a
             primary tumor

             * Patients may have had one prior systemic non-chemotherapeutic treatment (i.e.
             immunotherapy, receptor tyrosine kinase inhibitor, antiangiogenic agent,
             differentiating agent) for recurrent or metastatic disease

          -  Must have refused standard of care chemotherapy for metastatic disease

          -  Recovered from all acute side-effects (except alopecia) related to previous systemic
             therapy

          -  Absolute neutrophil count (ANC) >= 1,500/mm^3 (to be performed within 14 days prior to
             day 1 of protocol therapy)

             * NOTE: growth factor support is not permitted to normalize baseline ANC parameters,
             however subsequent growth factor administration is permitted as standard supportive
             care

          -  Platelets >= 100,000/mm^3 (to be performed within 14 days prior to day 1 of protocol
             therapy)

             * NOTE: transfusion of blood products are not allowed to normalize baseline blood
             parameters, however subsequent transfusions are allowed per standard supportive care
             guidelines

          -  Hemoglobin (HgB) >= 9.0 g/dL (to be performed within 14 days prior to day 1 of
             protocol therapy)

             * NOTE: transfusion of blood products are not allowed to normalize baseline blood
             parameters, however subsequent transfusions are allowed per standard supportive care
             guidelines

          -  Total serum bilirubin =< 2 x upper limit of normal (ULN) (to be performed within 14
             days prior to day 1 of protocol therapy)

          -  Aspartate aminotransferase (AST) =< 2.5 x ULN (to be performed within 14 days prior to
             day 1 of protocol therapy)

          -  Alanine aminotransferase (ALT) =< 2.5 x ULN (to be performed within 14 days prior to
             day 1 of protocol therapy)

          -  Creatinine =< 2.5 mg/dL (to be performed within 14 days prior to day 1 of protocol
             therapy)

        Exclusion Criteria:

          -  Prior radium Ra 223 dichloride

          -  Prior or concomitant chemotherapy for metastatic or recurrent disease with the
             following exceptions:

               -  Prior chemotherapy for local primary disease is permitted

               -  Bisphosphonates or receptor activator of nuclear factor kappa-Β (RANK) ligand
                  inhibitors are allowed at doses and schedule consistent with the treatment or
                  prevention of osteoporosis

          -  Prior radiation treatment for metastatic disease

          -  Concomitant radiation treatment to primary prostate site

          -  Orchiectomy

          -  Unstable medical comorbidities (i.e. uncontrolled cardiac comorbidities)

          -  Metastases that in the judgment of investigator-radiologist are not amenable to SBRT

          -  History of brain metastases or who currently have treated or untreated brain
             metastases

          -  Uncontrolled human immunodeficiency virus (HIV) infection

          -  Any other condition that would, in the investigator's judgement, contraindicate the
             patient's participation in the clinical study due to safety concerns with clinical
             study procedures

          -  Prospective participants who, in the opinion of the investigator, may not be able to
             comply with all study procedures (including compliance issues related to
             feasibility/logistics)