Adaptive radiotherapy using deformable image registration – a concept for individualised radiation treatments

We introduce a concept for continuous adaptation of radiation treatment plans and optimisation of dose distributions in treatments for head-and-neck cancer. This approach is based on a modified-daemons-type deformable image registration algorithm for the elastic propagation of tissue-delineations to consecutive CT-scans. We found that both dose coverage of target volumes and sparing of healthy tissues can be improved by using this approach. Furthermore our software enables us to prognosticate dosimetric changes based on statistical analysis of deformation vectors, thus reducing the reducing the workload in adaptive radiation therapy.