Combined hypofractionated stereotactic body radiotherapy with immunomodulating systemic therapy for inoperable recurrent head and neck cancer

Standard treatment for unresectable recurrent head-and-neck cancer (HNC) after radio(chemo)therapy is palliative systemic therapy or re-irradiation with or without systemic therapy. Re-irradiation can be curable, but low cure rates combined with high incidence of severe, even life-threatening late toxicity warrants investigating more tumor-selective radiation strategies. The combination of focused radiation using high fraction doses with immunomodulating agents arguably stand out as research direction to reduce local failure at the re-irradiated sites by direct and bystander mechanisms and to eradicate subclinical regional or distant disease by potential abscopal effects.