My surgeon's group suggested I could stretch out my testing to every 6 months after the 3 year mark. I told them (with the risk being what it was) I preferred to continue every 3 months for a full 5 years. My thought was; if there were any changes in the level of PSA, I would rather know sooner rather than later. I used the Memorial Sloan Kettering calculator for risk in my category and I felt as long as the 'risk' was substantial, better to stay on top of it. My cancer was T3b with SVI, and 4+3 (high risk). Also, my Decipher was considered high. I am now on 4 month intervals. Best, Tom