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Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators.

Publication ,  Journal Article
Belley, MD; Wang, C; Nguyen, G; Gunasingha, R; Chao, NJ; Chen, BJ; Dewhirst, MW; Yoshizumi, TT
Published in: Med Phys
March 2014

PURPOSE: Accurate dosimetry is essential when irradiating mice to ensure that functional and molecular endpoints are well understood for the radiation dose delivered. Conventional methods of prescribing dose in mice involve the use of a single dose rate measurement and assume a uniform average dose throughout all organs of the entire mouse. Here, the authors report the individual average organ dose values for the irradiation of a 12, 23, and 33 g mouse on a 320 kVp x-ray irradiator and calculate the resulting error from using conventional dose prescription methods. METHODS: Organ doses were simulated in the Geant4 application for tomographic emission toolkit using the MOBY mouse whole-body phantom. Dosimetry was performed for three beams utilizing filters A (1.65 mm Al), B (2.0 mm Al), and C (0.1 mm Cu + 2.5 mm Al), respectively. In addition, simulated x-ray spectra were validated with physical half-value layer measurements. RESULTS: Average doses in soft-tissue organs were found to vary by as much as 23%-32% depending on the filter. Compared to filters A and B, filter C provided the hardest beam and had the lowest variation in soft-tissue average organ doses across all mouse sizes, with a difference of 23% for the median mouse size of 23 g. CONCLUSIONS: This work suggests a new dose prescription method in small animal dosimetry: it presents a departure from the conventional approach of assigninga single dose value for irradiation of mice to a more comprehensive approach of characterizing individual organ doses to minimize the error and uncertainty. In human radiation therapy, clinical treatment planning establishes the target dose as well as the dose distribution, however, this has generally not been done in small animal research. These results suggest that organ dose errors will be minimized by calibrating the dose rates for all filters, and using different dose rates for different organs.

Duke Scholars

Published In

Med Phys

DOI

EISSN

2473-4209

Publication Date

March 2014

Volume

41

Issue

3

Start / End Page

034101

Location

United States

Related Subject Headings

  • X-Rays
  • Tomography, X-Ray Computed
  • Respiration
  • Reproducibility of Results
  • Radiometry
  • Radiation Dosage
  • Phantoms, Imaging
  • Nuclear Medicine & Medical Imaging
  • Monte Carlo Method
  • Mice
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Belley, M. D., Wang, C., Nguyen, G., Gunasingha, R., Chao, N. J., Chen, B. J., … Yoshizumi, T. T. (2014). Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators. Med Phys, 41(3), 034101. https://doi.org/10.1118/1.4864237
Belley, Matthew D., Chu Wang, Giao Nguyen, Rathnayaka Gunasingha, Nelson J. Chao, Benny J. Chen, Mark W. Dewhirst, and Terry T. Yoshizumi. “Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators.Med Phys 41, no. 3 (March 2014): 034101. https://doi.org/10.1118/1.4864237.
Belley MD, Wang C, Nguyen G, Gunasingha R, Chao NJ, Chen BJ, et al. Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators. Med Phys. 2014 Mar;41(3):034101.
Belley, Matthew D., et al. “Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators.Med Phys, vol. 41, no. 3, Mar. 2014, p. 034101. Pubmed, doi:10.1118/1.4864237.
Belley MD, Wang C, Nguyen G, Gunasingha R, Chao NJ, Chen BJ, Dewhirst MW, Yoshizumi TT. Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators. Med Phys. 2014 Mar;41(3):034101.

Published In

Med Phys

DOI

EISSN

2473-4209

Publication Date

March 2014

Volume

41

Issue

3

Start / End Page

034101

Location

United States

Related Subject Headings

  • X-Rays
  • Tomography, X-Ray Computed
  • Respiration
  • Reproducibility of Results
  • Radiometry
  • Radiation Dosage
  • Phantoms, Imaging
  • Nuclear Medicine & Medical Imaging
  • Monte Carlo Method
  • Mice