The overall aim of this project is to understand the role of nontrivial systematic errors in the overall accuracy of multileaf collimator (MLC) -based megavoltage (MV) photon-beam intensity modulated radiation therapy (IMRI-) delivery and dose calculation. According to our preliminary data, nontrivial systematic errors in IMRT delivery and plan calculation exist with significant frequency and have the potential to conspire to be clinically significant. A complete experimental characterization of static and dynamic MLC-based IMRT delivery is proposed. This experimental characterization includes the accurate simultaneous measurement of the dose distributions produced by IMRT using a novel radiochromic film dose-imaging system, and the delivered field shapes and fluences using a high-speed scintillation camera system. Results from this work will provide a ranking of the importance of the different sources of error for the development of strategies to minimize IMRT delivery errors. The data from this characterization will allow mechanical misalignment and dose delivery errors to be compensated for by incorporating the feedback of these measured parameters into a treatment-planning algorithm. From this vantage, the accuracy of the IMRT dose calculational algorithms will be assessed. Results from this work will provide a paradigm for closing the loop between the clinical treatment planning system and the MLC IMRT delivery system.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
1R01CA100636-01A1
Application #
6725890
Study Section
Radiation Study Section (RAD)
Program Officer
Deye, James
Project Start
2004-03-18
Project End
2008-02-29
Budget Start
2004-03-18
Budget End
2005-02-28
Support Year
1
Fiscal Year
2004
Total Cost
$235,799
Indirect Cost
Name
University of Florida
Department
Radiation-Diagnostic/Oncology
Type
Schools of Medicine
DUNS #
969663814
City
Gainesville
State
FL
Country
United States
Zip Code
32611
Li, Jonathan G; Yan, Guanghua; Liu, Chihray (2009) Comparison of two commercial detector arrays for IMRT quality assurance. J Appl Clin Med Phys 10:2942
Ranade, Manisha K; Li, Jonathan G; Dubose, Ryan S et al. (2008) A prototype quantitative film scanner for radiochromic film dosimetry. Med Phys 35:473-9
Fox, Christopher; Romeijn, H Edwin; Lynch, Bart et al. (2008) Comparative analysis of 60Co intensity-modulated radiation therapy. Phys Med Biol 53:3175-88
Lynch, Bart D; Kozelka, Jakub; Ranade, Manisha K et al. (2006) Important considerations for radiochromic film dosimetry with flatbed CCD scanners and EBT GAFCHROMIC film. Med Phys 33:4551-6
Ranade, Manisha K; Lynch, Bart D; Li, Jonathan G et al. (2006) A high-speed scintillation-based electronic portal imaging device to quantitatively characterize IMRT delivery. Med Phys 33:106-10
Fox, Christopher; Romeijn, H Edwin; Dempsey, James F (2006) Fast voxel and polygon ray-tracing algorithms in intensity modulated radiation therapy treatment planning. Med Phys 33:1364-71
Dempsey, James F; Romeijn, H Edwin; Li, Jonathan G et al. (2005) A fourier analysis of the dose grid resolution required for accurate IMRT fluence map optimization. Med Phys 32:380-8
Zeidan, Omar A; Li, Jonathan G; Low, Daniel A et al. (2004) Comparison of small photon beams measured using radiochromic and silver-halide films in solid water phantoms. Med Phys 31:2730-7