Combining prostate-specific antigen nadir and time to nadir allows for early identification of patients at highest risk for development of metastasis and death following salvage radiation therapy

Patients with a detectable nPSA also having a TnPSA < 6 months post-SRT are at high-risk for DM, PCSD, and decreased OS. These patients are unlikely to have clinically localized disease and should be considered for initiation of systemic therapies.