[Modern methods for cancer external radiation therapies].

Radiotherapy has been in constant progress for the past century. New technologies are based on modern imaging modalities, efficient 3D treatment planning systems, sophisticated immobilization systems and rigorous quality assurance and treatment verification. The central objective of conformal radiotherapy is to ensure a high dose distribution tailored to the limits of the target volume while reducing exposure of healthy tissues. These techniques would then allow a further tumor dose escalation. New systems like CyberKnife, tomotherapy and hadrontherapy represent major potential progress for the treatment of complex tumours that are very difficult to treat with conventional radiotherapy techniques.