Patients and their organs move, which means the tumor is also moving. This motion can result in the radiation beam missing its target. The most advanced method to evaluate and correct for this motion is to use Image Guided Radiation Therapy (IGRT).
What is IGRT?
All patients undergo a CT scan as part of the planning process. The information from the CT scan is then transmitted to a computer in the treatment room, and the radiation oncologist is able to compare the earlier image with images taken just before treatment to see if the treatment needs to be adjusted.
If the tumor has shifted, the radiation beams can then be corrected before the radiation treatment. This allows doctors to better target the tumor while avoiding surrounding healthy tissue.