This phase III/IV trial compares the impact of leuprolide and abiraterone acetate (AA) versus relugolix and AA on the heart in hormone-naive patients with advanced prostate cancer receiving pelvic radiation therapy. Leuprolide is in a class of medications called gonadotropin-releasing hormone agonists (GNRHa). It prevents the body from making luteinizing hormone-releasing hormone (LHRH) and luteinizing hormone (LH). This causes the testicles to stop making testosterone (a male hormone) in men and may stop the growth of prostate tumor cells that need testosterone to grow. Abiraterone acetate, an androgen biosynthesis inhibitor, works by decreasing the amount of certain hormones in the body. Relugolix, a GNRH antagonist, works by decreasing the amount of testosterone produced by the body. This may slow or stop the spread of prostate tumor cells that need testosterone to grow. The use of hormone therapy with radiation therapy has been shown to improve survival, however, studies have suggested that the addition of hormone therapy may worsen heart (cardiac) disease and high blood pressure. In fact, studies have shown that the most common cause of death in prostate cancer patients is due to heart disease or heart attacks. Computed tomography (CT) scans create a series of detailed pictures of areas inside the body; the pictures are created by a computer linked to an x-ray machine. In this study, sophisticated cardiac CT images are used to take pictures of patients' heart and coronary arteries to help assess damage to the heart. Using cardiac CT and blood tests, this trial may help doctors determine which patients are at risk of cardiac disease when treated with combination hormone therapy, as well as the differential risk of leuprolide versus relugolix in combination with abiraterone acetate.