From conventional radiation therapy to robotic approach: technological evolution and revolution of practice

Since the discovery of X-ray by Rontgen in 1895, the technological evolution of radiation therapy increased swiftly. However, the philosophy remained always the same: delivering higher radiation dose to the target volume while decreasing the dose to the organ at risk. Since the beginning of the 1990s, with conformal radiation therapy development (3DCT), differents techniques appeared. Some of them are derived from 3DCT, such as intensity-modulated radiation therapy, arctherapy, Tomotherapy (TM), or techniques using gating approach for breath holding. In the frame of stereotactic radiation therapy, the GammaKnife (TM) is already used since 20 years, while new concepts, based on a robotic approach (CyberKnife (TM)), are now available for treatment. Brachytherapy also took advantage from the technological evolution with the new approaches. In the frame of heavy ions, hadrontherapy represents an interesting technique dedicated to special clinical situations including pediatric tumors. In this article, we report an analysis of the technological evolution of radiation therapy.