(UroToday.com) Androgen receptor-targeted agents represent one of the main treatment options for men with metastatic castrate-resistant prostate cancer (mCRPC). The addition of stereotactic radiation therapy to ablate metastatic foci may improve clinical outcomes in oligometastatic setting. The ARTO trial (NCT03449719) is a randomized phase II trial testing the benefit of upfront stereotactic body radiation therapy on all sites of metastatic disease in oligometastatic-mCRPC patients undergoing first-line therapy with abiraterone acetate. At the 2021 American Society of Clinical Oncology Genitourinary Cancers annual meeting (ASCO GU), Dr. Giulio Francolini and colleagues presented a preliminary analysis, reporting results after six months of follow up, together with an exploratory analysis of androgen receptor splice variants (ARV7/ARFL) PSA and PSMA expression on circulating tumor cells detected in this cohort of patients.