Skip to main content

An investigation of the accuracy of an IMRT dose distribution using two- and three-dimensional dosimetry techniques.

Publication ,  Journal Article
Oldham, M; Sakhalkar, H; Guo, P; Adamovics, J
Published in: Med Phys
May 2008

Complex dose delivery techniques like intensity-modulated radiation therapy (IMRT) require dose measurement in three dimensions for comprehensive validation. Previously, we demonstrated the feasibility of the "PRESAGE/optical-computed tomography (CT)" system for the three-dimensional verification of simple open beam dose distributions where the planning system was known to be accurate. The present work extends this effort and presents the first application of the PRESAGE/optical-CT system for the verification of a complex IMRT distribution. A highly modulated 11 field IMRT plan was delivered to a cylindrical PRESAGE dosimeter (16 cm in diameter and 11 cm in height), and the dose distribution was readout using a commercial scanning-laser optical-CT scanner. Comparisons were made with independent GAFCHROMIC EBT film measurements, and the calculated dose distribution from a commissioned treatment planning system (ECLIPSE). Isodose plots, dose profiles, gamma maps, and dose-volume histograms were used to evaluate the agreement. The isodose plots and dose profiles from the PRESAGE/optical-CT system were in excellent agreement with both the EBT measurements and the ECLIPSE calculation at all points except within 3 mm of the outer edge of the dosimeter where an edge artifact occurred. Excluding this 3 mm rim, gamma map comparisons show that all three distributions mutually agreed to within a 3% (dose difference) and 3 mm (distance-to-agreement) criteria. A 96% gamma pass ratio was obtained between the PRESAGE and ECLIPSE distributions over the entire volume excluding this rim. In conclusion, for the complex IMRT plan studied, and in the absence of inhomogeneities, the ECLIPSE dose calculation was found to agree with both independent measurements, to within 3%, 3 mm gamma criteria.

Duke Scholars

Published In

Med Phys

DOI

ISSN

0094-2405

Publication Date

May 2008

Volume

35

Issue

5

Start / End Page

2072 / 2080

Location

United States

Related Subject Headings

  • Tomography, X-Ray Computed
  • Software
  • Reproducibility of Results
  • Radiotherapy, Intensity-Modulated
  • Radiotherapy Planning, Computer-Assisted
  • Radiotherapy Dosage
  • Radiometry
  • Quality Control
  • Nuclear Medicine & Medical Imaging
  • Humans
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Oldham, M., Sakhalkar, H., Guo, P., & Adamovics, J. (2008). An investigation of the accuracy of an IMRT dose distribution using two- and three-dimensional dosimetry techniques. Med Phys, 35(5), 2072–2080. https://doi.org/10.1118/1.2899995
Oldham, Mark, Harshad Sakhalkar, Pengyi Guo, and John Adamovics. “An investigation of the accuracy of an IMRT dose distribution using two- and three-dimensional dosimetry techniques.Med Phys 35, no. 5 (May 2008): 2072–80. https://doi.org/10.1118/1.2899995.
Oldham M, Sakhalkar H, Guo P, Adamovics J. An investigation of the accuracy of an IMRT dose distribution using two- and three-dimensional dosimetry techniques. Med Phys. 2008 May;35(5):2072–80.
Oldham, Mark, et al. “An investigation of the accuracy of an IMRT dose distribution using two- and three-dimensional dosimetry techniques.Med Phys, vol. 35, no. 5, May 2008, pp. 2072–80. Pubmed, doi:10.1118/1.2899995.
Oldham M, Sakhalkar H, Guo P, Adamovics J. An investigation of the accuracy of an IMRT dose distribution using two- and three-dimensional dosimetry techniques. Med Phys. 2008 May;35(5):2072–2080.

Published In

Med Phys

DOI

ISSN

0094-2405

Publication Date

May 2008

Volume

35

Issue

5

Start / End Page

2072 / 2080

Location

United States

Related Subject Headings

  • Tomography, X-Ray Computed
  • Software
  • Reproducibility of Results
  • Radiotherapy, Intensity-Modulated
  • Radiotherapy Planning, Computer-Assisted
  • Radiotherapy Dosage
  • Radiometry
  • Quality Control
  • Nuclear Medicine & Medical Imaging
  • Humans