[How to improve radiotherapy ? Technological developments and radiotherapy of tomorrow]

Radiotherapy established itself in the 20th century as an essential modality in the fight against cancer. The major technological advances of the last decades have allowed a considerable improvement in the therapeutic window. They have also paved the way for stereotactic radiotherapy and new indications. The aim of this article is to enable readers to understand external radiotherapy in 2021 and to understand the challenges of tomorrow. Three areas of improvement in the discipline will be described, the optimization of the prescribed therapeutic dose, the improvement of the distribution of this dose and, finally, the better understanding of radiobiology. For each of these axes, the current implications will be described as well as those which could/should have a major impact on the radiotherapy. FLASH radiotherapy will also be discussed.