High-Risk Metachronous Oligometastatic Prostate Cancer Trial

This trial is for men with prostate cancer that has spread to a small number of new spots (called oligometastatic disease) after initial treatment, who also carry certain high-risk inherited gene mutations. The study is testing whether targeted radiation (called SABR) to those few spots can delay or prevent further spread and improve outcomes in this genetically high-risk group. **You may be eligible if...** - You are 18 or older with confirmed prostate cancer - Your cancer has developed 1 to 3 new tumor spots (or up to 5 on advanced imaging) in the past 6 months, each smaller than 5 cm - You carry a high-risk gene mutation such as BRCA1, BRCA2, TP53, ATM, PALB2, or similar - Your PSA is between 0.5 and 50 - Your PSA doubling time is less than 15 months - Your testosterone level is above 100 ng/dL - You have a life expectancy of at least 12 months **You may NOT be eligible if...** - You do not carry one of the specified gene mutations - Your testosterone is suppressed from hormone therapy (below 100 ng/dL) - You have more than 3 tumor spots (or 5 on PET scan) - Your PSA is below 0.5 or above 50 - You have certain other serious health conditions that would prevent safe treatment Talk to your doctor to see if this trial is right for you.