Adaptive radiotherapy involves acquisition and processing of image data from numerous devices at various time scales. In contrast to conventional radiotherapy which mainly involves unidirectional flow of image data in fairly large steps ‐ from the scanners to the planners to the treatment machines ‐ adaptive radiotherapy involves a bidirectional and iterative flow of image data. Acquisition and processing of multimodality imaging data for the initial planning step is now common place: x‐ray CT provides accurate geometric and density information; MR provides exquisite soft tissue contrast; and nuclear medicine imaging provides unique metabolic information. Data from these modalities are registered and integrated to help define the tumor volume(s) and surrounding healthy tissues. These modalities along with ultrasound and optical imaging can also provide 4D and time series image data to help model moment‐to‐moment physiologic motion and day‐to‐day functional and anatomic changes. Tracking these changes between and during treatment fractions is a key aspect of the adaptive radiotherapy process. Image processing steps required to support this tracking and adaptation of treatments include deformable image registration, contour propagation, and dose accumulation. The outputs of these steps are used to support decisions about maintaining or adapting the current treatment plan. This course will provide an overview of the different imaging devices used to support adaptive radiotherapy and highlight the benefits and challenges of each. The details of the various image processing tools used to extract, combine, and analyze the information from the various imaging data will also be presented. Finally, the effective use of these devices and tools for the adaptive radiotherapy process will be described and elucidated using several clinical examples. Learning Objectives: 1. Understand the basic principles of image acquisition used in adaptive radiotherapy 2. Understand the basic principles of image processing used in adaptive radiotherapy 3. Understand how imaging and image processing are used in the adaptive radiotherapy process.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging