Experimental verification of a real-time compensation functionality for dose changes due to target motion in scanned particle therapy

Journal Article · Sat Oct 15 04:00:00 EDT 2011 · Medical Physics

DOI:https://doi.org/10.1118/1.3633891· OSTI ID:22098638

Luechtenborg, Robert; Saito, Nami; Durante, Marco; Bert, Christoph ^[1]

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1. GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt, Germany Technische Universitaet Darmstadt, Institut fuer Festkoerperphysik, Hochschulstrasse 6-8, 64289 Darmstadt (Germany)

Purpose: Implementation and experimental assessment of a real-time dose compensation system for beam tracking in scanned carbon beam therapy of intrafractionally moving targets. Methods: A real-time dose compensation functionality has been developed and implemented at the experimental branch of the beam tracking system at GSI Helmholtzzentrum fuer Schwerionenforschung (GSI). Treatment plans for different target geometries have been optimized. They have been delivered using scanned carbon ions with beam tracking (BT) and real-time dose compensation combined with beam tracking (RDBT), respectively. Target motion was introduced by a rotating table. Dose distributions were assessed by ionization chamber measurements and dose reconstructions. These distributions have been compared to stationary delivery for BT as well as RDBT. Additionally simulations have been performed to investigate the dependence of delivered dose distributions on varying motion starting phases for BT and RDBT, respectively. Results: Average measured dose differences between static delivery and motion influenced delivery could be reduced from 27-68 mGy when BT was used to 12-37 mGy when RDBT was used. Nominal dose was 1000 mGy. Simulated dose deliveries showed improvements in dose delivery and robustness against varying starting motion phases when RDBT was used. Conclusions: A real-time dose compensation functionality extending the existing beam tracking functionality has been implemented and verified by measurements. Measurements and simulated dose deliveries show that real-time dose compensation can substantially improve delivered dose distributions for large rotational target motion compared to beam tracking alone.

• OSTI ID: 22098638
• Journal Information: Medical Physics, Journal Name: Medical Physics Journal Issue: 10 Vol. 38; ISSN 0094-2405; ISSN MPHYA6
• Country of Publication: United States
• Language: English

Related Subjects

61 RADIATION PROTECTION AND DOSIMETRY
62 RADIOLOGY AND NUCLEAR MEDICINE
BEAMS
CARBON
DISTRIBUTION
DOSIMETRY
IONIZATION CHAMBERS
RADIATION DOSE DISTRIBUTIONS
RADIATION DOSES
RADIOTHERAPY
SIMULATION