Research

Motion compensation with a scanned ion beam: a technical feasibility study

Sven Oliver Grözinger , Christoph Bert , Thomas Haberer , Gerhard Kraft and Eike Rietzel

Gesellschaft für Schwerionenforschung (GSI), Abteilung Biophysik, Planckstraße 1, 64291 Darmstadt, Germany

author email corresponding author email

Radiation Oncology 2008, 3:34doi:10.1186/1748-717X-3-34

Published:	14 October 2008

Abstract

Background

Intrafractional motion results in local over- and under-dosage in particle therapy with a scanned beam. Scanned beam delivery offers the possibility to compensate target motion by tracking with the treatment beam.

Methods

Lateral motion components were compensated directly with the beam scanning system by adapting nominal beam positions according to the target motion. Longitudinal motion compensation to mitigate motion induced range changes was performed with a dedicated wedge system that adjusts effective particle energies at isocenter.

Results

Lateral compensation performance was better than 1% for a homogeneous dose distribution when comparing irradiations of a stationary radiographic film and a moving film using motion compensation. The accuracy of longitudinal range compensation was well below 1 mm.

Conclusion

Motion compensation with scanned particle beams is technically feasible with high precision.