Fig. 1.

Schematic overview over the model and the differential equations describing its dynamic behavior. Immune response (ω₁), induced by lymphocytes, exert a cytotoxic effect on both irradiated tumor and nonirradiated tumor cells. Immune response can be upregulated by the injection of Programmed Death-Ligand 1 (PD-L1) immune checkpoint inhibitors (durvalumab, red-marked new terms). Lightning symbolizes the radiation delivered to the primary liver cancer and circulating lymphocytes. Radiation dose to circulating lymphocyte is calculated explicitly using previously developed methods.¹¹