Real-Time Tumor Localization
Ruijiang Li, Laura Cerviño, Steve B Jiang · 2011
A critical step for motion-adaptive radiotherapy is the precise localization of the tumor in real time. An ideal localization system for radiotherapy should possess certain desirable properties (Dieterich et al. 2008). First, it has to be suciently accurate to capture real-time tumor motion and deformation caused by any physiological processes, such as respiration. Second, it should be also capable of imaging and localizing the surrounding structures in addition to the tumor. Last but not least, it should be noninvasive and present only minimal additional risk to the patient. Such an ideal localization system does not currently exist in clinics. However, there are several localization systems in current use or under active development that meet at least part of the above requirements for an ideal localization system. In the following sections, rst we review these localization systems in detail. ese cover a wide range of modern medical imaging modalities, including radiography, electronic portal imaging device (EPID), magnetic resonance imaging (MRI), ultrasound, radio frequency electromagnetic (EM) wave, optical, and positron emission, etc. Some are already commercially available and have been extensively used in clinics; some are under active development, while still others are research topics. en we discuss dierent localization methods, given the hardware settings in dierent localization systems. Finally, we summarize and conclude our discussion.