TY  - JOUR
AU  - Henkner, K.
AU  - Winter, M.
AU  - Echner, G.
AU  - Ackermann, B.
AU  - Brons, S.
AU  - Horn, J.
AU  - Jäkel, O.
AU  - Karger, Christian
TI  - A motorized solid-state phantom for patient-specific dose verification in ion beam radiotherapy.
JO  - Physics in medicine and biology
VL  - 60
IS  - 18
SN  - 1361-6560
CY  - Bristol
PB  - IOP Publ.
M1  - DKFZ-2017-02737
SP  - 7151 - 7163
PY  - 2015
AB  - For regular quality assurance and patient-specific dosimetric verification under non-horizontal gantry angles in ion beam radiotherapy, we developed and commissioned a motorized solid state phantom. The phantom is set up under the selected gantry angle and moves an array of 24 ionization chambers to the measurement position by means of three eccentrically-mounted cylinders. Hence, the phantom allows 3D dosimetry at oblique gantry angles. To achieve the high standards in dosimetry, the mechanical and dosimetric accuracy of the phantom was investigated and corrections for residual uncertainties were derived. Furthermore, the exact geometry as well as a coordinate transformation from cylindrical into Cartesian coordinates was determined. The developed phantom proved to be suitable for quality assurance and 3D-dose verifications for proton- and carbon ion treatment plans at oblique gantry angles. Comparing dose measurements with the new phantom under oblique gantry angles with those in a water phantom and horizontal beams, the dose deviations averaged over the 24 ionization chambers were within 1.5
LB  - PUB:(DE-HGF)16
C6  - pmid:26334387
DO  - DOI:10.1088/0031-9155/60/18/7151
UR  - https://inrepo02.dkfz.de/record/126709
ER  -