ABSTRACT
This chapter describes multimodality imaging in radiotherapy in more detail using two specific tumor sites as examples: fluorodeoxyglucose positron emission tomography for lung cancer and magnetic resonance imaging for cervix cancer. These examples demonstrate the current use of multimodality imaging for treatment planning, response assessment, and adaptive treatment opportunities. Technical aspects of integrating multimodality imaging into the radiotherapy workflow are addressed, and future directions of multimodality imaging are explored. To be of use for radiotherapy applications, images must first be brought into spatial alignment with each other. The process of determining such spatial alignment is called image registration. Registration proceeds by identifying corresponding points, features, or regions between images and then solving for a transformation that would map the locations of these regions from one image to another based on this information. In addition, robust registration methods are still under development to accommodate large deformations between images obtained at different times with different patient poses.
