Deformable Image Registration (DIR) plays a central role in many advanced radiotherapy applications involving the use of multimodal images, time series, and anatomical atlases for assisted contouring. Moreover, DIR is an essential element of “adaptive radiotherapy”, since it is used for the automatic propagation of the contours and dose accumulation on images acquired during treatment, with the aim of detecting events that may require changes in the treatment plan. Thus, DIR results are used in processes for determining the planning or modification of therapeutic methods. Then, the knowledge of uncertainties associated with image registration software is essential. However, despite the diffusion of solutions implementing DIR, both in stand-alone systems and integrated into TPSs, correct application and quality assurance of DIR are open questions. This course will describe the theoretical basis of DIR and will show some examples of its application in clinical practice, focusing on quality assurance.
The goal of the course is to give operators useful information and operational instruments for the clinical implementation of the DIR, being aware of the limits and the value of the currently available systems.