High-dose irradiation in combination with non-ablative low-dose radiation to treat metastatic disease after progression on immunotherapy: Results of a phase II trial

Highlights: • HD-RT ± LD-RT to separate lesions can be safely delivered for IO refractory patients. • HD-RT + LD-RT safely improved lesion-specific response for IO refractory patients. • LD-RT may be a consideration for large tumors or multiple isocenters. • T- and NK cell infiltration was enhanced in lesions treated with LD-RT. To report early findings from a phase II trial of high-dose radiotherapy (HD-RT) with or without low-dose RT (LD-RT) for metastatic cancer.