Is there a role for RT in localized nodal relapse of stage IV follicular lymphoma with the goal of delaying the need for additional systemic therapy?

For example, in a patient treated with multiple systemic therapies over ~10 years, would it be reasonable to use radiation to a single asymptomatic site of nodal progression? Would your answer change if the patient had experienced significant complications with prior systemic therapy (such as systemic zoster infection)? Does advanced age (80+) factor in to your recommendations?