Do distant lymph nodes from metastatic prostate cancer (retroperitoneal and SCV) count as oligometastatic disease?   

A patient had limited metastatic prostate cancer several years ago and was treated with orchiectomy only, and recently had Xtandi added. PSA remains detectable at 0.5. Restaging PSMA PETCT shows activity in the prostate, a couple of retroperitoneal nodes (not pelvic) and also a small but clearly avid left SCV node. He is referred for comprehensive treatment of oligometastatic prostate cancer. 

Is it reasonable to treat all disease in this patient? Would you treat the retroperitoneal chains or the individual nodes? What dose and fractionation would you use for the SCV node?