Modern radiation therapy modalities, for example, intensity modulated radiation therapy (IMRT), are associated with highly conformal dose distributions with steep gradients. Commissioning of these modalities requires the use of multidimensional dosimeters which have been under intense research and development. A recent report from the Radiological Physics Center (RPC) revealed that roughly 30% of institutions failed to deliver a dose distribution to a head-and-neck phantom that agrees with their own treatment plan to within 7% or 4 mm. The RPC report provides strong evidence that IMRT implementation is prone to error and that improved quality assurance tools are required. The overarching hypothesis of this research is that a low-Z KCl:Eu2+ storage phosphor film (SPF) will provide the first 2D dosimeter capable of conducting benchmark dosimetry measurements, substantially improving the commissioning and quality assurance of radiation therapy treatment planning and delivery systems.
Our first aim i s to optimize KCl:Eu2+ storage phosphor particle composition and chemical structure to maximize radiation sensitivity, radiation hardness, response uniformity, and signal stability.
Our second aim i s to develop a process to fabricate an SPF by evaporating the optimized storage phosphor developed in aim 1 to a thickness on the order of one micron using physical vapor deposition onto a nearly water-equivalent substrate.
Our third aim i s to demonstrate that the SPF dosimeter developed in aim 2 will provide benchmark-quality dose distribution measurements and to demonstrate the flexibility of the SPF fabrication process by building planar and cylindrical dosimeters.

Public Health Relevance

The successful completion of this research will provide the radiation oncology community with the first two-dimensional dosimeter prototype capable of acquiring benchmark dose measurements. This will be critical for the safe and efficient utilization of modern, complex radiation delivery techniques such as IMRT.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA148853-02
Application #
8096736
Study Section
Radiation Therapeutics and Biology Study Section (RTB)
Program Officer
Deye, James
Project Start
2010-09-01
Project End
2014-06-30
Budget Start
2011-07-01
Budget End
2012-06-30
Support Year
2
Fiscal Year
2011
Total Cost
$305,938
Indirect Cost
Name
Washington University
Department
Radiation-Diagnostic/Oncology
Type
Schools of Medicine
DUNS #
068552207
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
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Xiao, Zhiyan; Mazur, Thomas R; Driewer, Joseph P et al. (2015) The role of oxygen in the photostimulation luminescence process of europium doped potassium chloride. Radiat Meas 76:23-28
Li, H Harold; Rodriguez, Vivian L; Green, Olga L et al. (2015) Patient-specific quality assurance for the delivery of (60)Co intensity modulated radiation therapy subject to a 0.35-T lateral magnetic field. Int J Radiat Oncol Biol Phys 91:65-72
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Hansel, Rachael A; Xiao, Zhiyan; Zhang, Lei et al. (2014) X ray storage performance of KCl:Eu(2+) with high cumulated dose. Nucl Instrum Methods Phys Res B 326:178-181
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Hansel, Rachael A; Xiao, Zhiyan; Hu, Yanle et al. (2013) The role of activator concentration and precipitate formation on optical and dosimetric properties of KCl:Eu(2+) storage phosphor detectors. Med Phys 40:092104
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Xiao, Zhiyan; Hansel, Rachael; Chen, Haijian et al. (2013) Temporal signal stability of KCl:Eu(2+) storage phosphor dosimeters. Med Phys 40:021721
Driewer, Joseph P; Chen, Haijian; Osvet, Andres et al. (2011) Radiation hardness of the storage phosphor europium doped potassium chloride for radiation therapy dosimetry. Med Phys 38:4681-8

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