A method for identifying a patient for cancer therapy can include administering a diagnostic dose of a detectably labeled first binding agent to a patient, the detectably labeled binding agent being capable of binding a molecular target. The method also includes selecting a patient for administration of a therapeutic dose of a second binding agent capable of binding a cellular target, wherein the selected patient exhibits a positive reading for the detectably labeled first binding agent. Furthermore, the method can include administering a therapeutic dose of the second binding agent to the patient.