Radiation Protection Dosimetry Advance Access published online on November 4, 2009
Radiation Protection Dosimetry, doi:10.1093/rpd/ncp257
ESTIMATION OF ABSORBED DOSES FROM PAEDIATRIC CONE-BEAM CT SCANS: MOSFET MEASUREMENTS AND MONTE CARLO SIMULATIONS
1 Medical Physics Graduate Program, Duke University, Durham NC 27705, USA
2 Division of Radiation Safety, Duke University Medical Center, Durham NC 27710, USA
3 Department of Radiology, Duke University Medical Center, Durham NC 27710, USA
4 Department of Radiation Oncology, Duke University Medical Center, Durham NC 27710, USA
* Corresponding author: yoshi003{at}mc.duke.edu
Received May 1, 2009, amended October 6, 2009, accepted October 15, 2009
The purpose of this study was to establish a dose estimation tool with Monte Carlo (MC) simulations. A 5-y-old paediatric anthropomorphic phantom was computed tomography (CT) scanned to create a voxelised phantom and used as an input for the abdominal cone-beam CT in a BEAMnrc/EGSnrc MC system. An X-ray tube model of the Varian On-Board Imager® was built in the MC system. To validate the model, the absorbed doses at each organ location for standard-dose and low-dose modes were measured in the physical phantom with MOSFET detectors; effective doses were also calculated. In the results, the MC simulations were comparable to the MOSFET measurements. This voxelised phantom approach could produce a more accurate dose estimation than the stylised phantom method. This model can be easily applied to multi-detector CT dosimetry.