München 2009 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

ST: Fachverband Strahlen- und Medizinphysik

ST 7: Ion Radiation Therapy 2: Target Motion Management

ST 7.1: Talk

Wednesday, March 11, 2009, 15:30–15:45, A021

Motion management in radiation therapy — •Christoph Bert — GSI Helmholtzzentrum für Schwerionenforschung, Abteilung Biophysik, Darmstadt, Germany

Radiotherapy of tumors that move during irradiation requires dedicated means to ensure target coverage despite the motion influence. Motion can occur inter-fractionally (e.g. position of the prostate) or intra-fractionally; the most dominant reason for intra-fractional motion is respiration. The standard procedure to reduce the influence of target motion is the use of margins encompassing the clinical target volume (CTV) to form a planning target volume (PTV) that covers all uncertainties. This approach ensures CTV coverage for most treatment modalities but results in therapeutic dose to normal tissue.

With the opportunities given by improved imaging techniques such as time-resolved computed tomography (CT) or (cone-beam) CT in treatment position as well as motion mitigation techniques such as gating or tracking the dosimetric influence of target motion could be reduced. Especially for conformal techniques such as intensity modulated radiotherapy (IMRT) or particle therapy only advanced motion mitigation techniques and/or adaptive therapy concepts lead to preservation of the target conformation established for stationary targets in treatments of moving targets.

In the scope of the talk an introduction to motion management will be given with an emphasis on application in scanned particle beam therapy.