Three- and Four-Dimensional Morphological Imaging for Adaptive Radiation Therapy Planning

Onboard volumetric imaging is developing to meet the increased needs for accurate patient setup in modern radiation therapy (RT) techniques such as intensity-modulated RT (IMRT) and volumetric-modulated arc therapy (VMAT). Although exquisite dose distribution can be planned, how to deliver the dose to the right volume at the right time has become increasingly important. Ÿe development of modern therapy techniques has not occurred very meaningfully and it could even be harmful if there is no e¢ective way of ensuring patient setup and accurate delivery (Xing et al. 2006; Timmerman and Xing 2009).