Workpackage 2

Development of adaptive radiotherapy techniques to optimally account for the temporally variant patient model

Geometrical uncertainties such as patient setup variability and (respiration-induced) organ motion limit the precision of radiotherapy delivery. Consequently, the actually delivered dose does not equal the planned dose (what you see is not what you get). Recent developments in image guided radiotherapy allow visualizing the target and OAR just prior to treatment, assessing geometrical discrepancies between planning and delivery, and aligning the target to the planned position using a couch shift to increase the precision of radiotherapy. However, in the case of more complex changes such as relative position changes of tumour and involved lymph nodes, posture changes, e.g. neck flex and tumour response, such a correction is inadequate to increase the precision of RT delivery.

Adaptive radiotherapy, where 1) repetitive imaging of the patient is employed to characterize the patient-specific variabilities and longitudinal changes and 2) these changes are accounted for in a adaptive plan modification, has the potential to correct for complex geometrical variability. In this work package we will develop adaptive radiotherapy techniques for head-and-neck and lung cancer patients and implement these techniques in the clinical trials of this project to maximize their efficacy and safety.

The NKI (Amsterdam) and RaySearch (Stockholm) are collaborating on this workpackage.