FIGURE 1.

The anti-tumour activity of radiation therapy (RT) is multi-faceted. Tumour irradiation induces both direct and indirect effects in controlling the tumour. Direct effects are the result of significant radiation-induced DNA damage in cancer cells leading to their death, which may occur at various time points after the initial irradiation event. Radiation therapy (RT) also exerts anti-tumour activity via indirect effects, which include, but are not limited to, injury of tumour vasculature and priming of host anti-tumour immune responses. A range of factors influence the triggering and magnitude of these effects, broadly falling into cell-intrinsic, radiation, and microenvironment factors. A deeper knowledge of the underpinning mechanisms and their interplay will reveal opportunities for enhancing the overall anti-tumour activity of RT. ATM, ataxia-telangiectasia mutated. DAMP, danger associated-molecular pattern.