Original Publication Date: 1 June, 2014
Publication / Source: Colorectal Cancer
Authors: Te Vuong, Aurelie Garant, Fleure Gallant
Intensity-modulated radiation therapy
The introduction of computed tomography simulation and computer-based treatment planning in radiotherapy provided improved definition of target and normal structures, and lead to the era of 3D conformal therapy. However, it was the modern generation of linear accelerators, equipped with dynamic multileaf collimators, that truly revolutionized radiotherapy. Multileaf collimators consist of multiple, individually motorized leaves that are driven by sophisticated computerized algorithms, moving them in and out of the beam’s path, thereby modulating the beam’s intensity. These technological advancements precipitated the development of intensity-modulated radiotherapy (IMRT), enabling highly conformal radiation delivery with dose sculpting of target volumes and a rapid dose fall-off for the sparing of normal structures, or ‘organs at risk’ (OAR).