[Angiogenesis and radiotherapy (vessels, anaemia, oxygen and radiosensitivity)].

Oxygen plays a direct role in cell death after exposure to ionizing radiations and tumour hypoxia, favoured by anaemia, is a factor of poor treatment response. Tumour phenotype is directly influenced by tissue oxygenation, inducing tumour cells adaptation to the environment and potential resistance to treatment. The correction of tumour hypoxia can increase treatment response. It is however difficult to directly correlate pO2 and vascularisation. Vessels from angiogenesis get endothelial cells but have lost the functions of normal vessels (receptors, muscles...). The role of angiogenesis has been demonstrated on initial tumour growth and on metastatic potential and regulation. Many pre clinical studies have demonstrated the benefit of combining anti angiogenic compounds and cytotoxic agents (chemotherapy drugs and ionizing radiations). Clinical studies are on going and new evaluation models of treatment response will be necessary.