PO-1026 Re-irradiation with concurrent Nivolumab in locally recurrent Head and Neck Cancer. (August 2021) - von der Grün, J.; Altay-Langguth, A.; Balermpas, P.; Brandts, C.; Balster, S.; Ghanaati, S.; Winkelmann, R.; Burck, I.; Rödel, F.; Martin, D.; Rödel, C.