TU-G-BRCD-03: Managing Patient and Organ Motion in Proton Therapy

The advent of proton based therapy has provided excitement in the radiation oncology community. Not in the least due to the theoretically advantageous geometrical properties of the dose deposition by such charged particles. In this presentation I will discuss the some of the challenges, which can make this tool sub-optimal when used in clinical practice with actual patients.

Data and analysis on patient setup variations and organ movement, gathered from "classical" photon therapy is projected to this new modality. Inter and intra fractional movement will be covered as well as the notion of margin determination in order to provide adequate coverage and in what way this makes sense. In addition, the time frame with which these uncertainties occur implies that different measures need to be taken and the use of in room imaging might be needed. Further, the advent of scanning techniques again provide an advantage as well as a disadvantage as far as movement is concerned.

Proton therapy is a promising technique and exciting on a clinical and scientific level. In order to show significant improvement, knowledge with regard to targfet determination, as well as positioning is more critical in comparison with the classical modalities.

1. Knowledge on patient and/or organ movements motion effects. 2. Categorizing the movement in time and space. 3. Reflections on the impact of movement on proton based treatments.