Patients receive enzalutamide orally (PO) once daily (QD) for 6 months. Beginning 2 weeks after start of enzalutamide, patients receive LHRH agonist therapy with goserelin acetate subcutaneously (SC) or leuprolide acetate intramuscularly (IM) or SC for 6 months (intermediate risk patients) or 24 months (high risk patients) post-radiation therapy. Beginning 8 weeks after the start of LHRH agonist therapy, patients undergo either intensity modulated radiation therapy (IMRT) or volumetric arc therapy (VMAT) daily five days a week for 8 weeks.