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Target motion tracking with a scanned particle beam
Author(s) -
Bert Christoph,
Saito Nami,
Schmidt Alexander,
Chaudhri Naved,
Schardt Dieter,
Rietzel Eike
Publication year - 2007
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.2815934
Subject(s) - tracking (education) , tracking system , detector , optics , particle therapy , physics , beam (structure) , nuclear physics , psychology , pedagogy , large hadron collider
Treatment of moving targets with scanned particle beams results in local over‐ and under‐dosage due to interplay of beam and target motion. To mitigate the impact of respiratory motion, a motion tracking system has been developed and integrated in the therapy control system at Gesellschaft für Schwerionenforschung. The system adapts pencil beam positions as well as the beam energy according to target motion to irradiate the planned position. Motion compensation performance of the tracking system was assessed by measurements with radiographic films and a 3D array of 24 ionization chambers. Measurements were performed for stationary detectors and moving detectors using the tracking system. Film measurements showed comparable homogeneity inside the target area. Relative differences of 3D dose distributions within the target volume were 1 ± 2 % with a maximum of 4 % . Dose gradients and dose to surrounding areas were in good agreement. The motion tracking system successfully preserved dose distributions delivered to moving targets and maintained target conformity.