The abscopal effect refers to the ability of a local therapy (e.g., RT, radiofrequency ablation) delivered to 1 or more sites to generate an immune response at distant sites of Dz. Preclinical and clinical studies suggest local RT damages DNA within tumor cells leading to tumor-cell apoptosis/necrosis and tumor-antigen release. These tumor antigens induce antitumor-specific immune responses systemically using similar pathways by which viral/bacterial antigens cause systemic immunity. Abscopal responses d/t RT alone are very rare but appear more common in the setting of checkpoint inhibitors.