This trial studies how well apalutamide, with or without precise radiation therapy (SBRT), works in treating prostate cancer that resists typical hormone treatments. Apalutamide blocks testosterone, which helps slow cancer growth. SBRT uses focused radiation to kill cancer cells while sparing healthy tissue. The goal is to see if combining these treatments is more effective than using apalutamide alone. Apalutamide is a newer anti-androgen drug that has shown promise in improving the effectiveness of radiotherapy in prostate cancer treatment.