Figure 1.

Schematic overview of the enhanced effectiveness of radiotherapy or chemotherapy with hyperthermia. (A) Hyperthermia can temporarily inhibit repair of radiotherapy or chemotherapy induced DNA damage, resulting in increased tumor cell kill. (B) Hyperthermia has effects on both the tumor microenvironment and the tumor cell itself. Already at lower temperatures, starting at 39°C, hyperthermia can disturb the tumor microenvironment by increased perfusion and reoxygenation. Moreover, heat was found to attract immune cells into the tumor microenvironment. Starting at 41°C, hyperthermia can temporarily inhibit DNA repair pathways, resulting in an accumulation of DNA breaks and thereby causing cell cycle arrest. Subsequently, failure to repair DNA breaks causes cell death, such as by apoptosis.