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Optimizing monoscopic kV fluoro acquisition for prostate intrafraction motion evaluation.

Publication ,  Journal Article
Adamson, J; Wu, Q
Published in: Phys Med Biol
January 7, 2009

Monoscopic kV imaging during radiotherapy has been recently implemented for prostate intrafraction motion evaluation. However, the accuracy of 3D localization techniques from monoscopic imaging of prostate and the effect of acquisition parameters on the 3D accuracy have not been studied in detail, with imaging dose remaining a concern. In this paper, we investigate methods to optimize the kV acquisition parameters and imaging protocol to achieve improved 3D localization and 2D image registration accuracy for minimal imaging dose. Prostate motion during radiotherapy was simulated using existing cine-MRI measurements, and was used to investigate the accuracy of various 3D localization techniques and the effect of the kV acquisition protocol. We also investigated the relationship between mAs and the accuracy of the 2D image registration for localization of fiducial markers and we measured imaging dose for a 30 cm diameter phantom to evaluate the necessary dose to achieve acceptable image registration accuracy. Simulations showed that the error in assuming the shortest path to localize the prostate in 3D using monoscopic imaging during a typical IMRT fraction will be less than approximately 1.5 mm for 95% of localizations, and will also depend on prostate motion distribution, treatment duration and image acquisition and treatment protocol. Most uncertainty cannot be reduced from higher imaging frequency or acquiring during gantry rotation between beams. Measured maximum surface dose to the cylindrical phantom from monoscopic kV intrafraction acquisitions varied between 0.4 and 5.5 mGy, depending on the acquisition protocol, and was lower than the required dose for CBCT (21.1 mGy). Imaging dose can be lowered by approximately 15-40% when mAs is optimized with acquisition angle. Images acquired during MV beam delivery require increased mAs to obtain the same level of registration accuracy, with mAs/registration increasing roughly linearly with field size and dose rate.

Duke Scholars

Published In

Phys Med Biol

DOI

ISSN

0031-9155

Publication Date

January 7, 2009

Volume

54

Issue

1

Start / End Page

117 / 133

Location

England

Related Subject Headings

  • Time Factors
  • Sensitivity and Specificity
  • Radiation Dosage
  • Prostate
  • Nuclear Medicine & Medical Imaging
  • Movement
  • Models, Biological
  • Male
  • Magnetic Resonance Imaging
  • Imaging, Three-Dimensional
 

Citation

APA
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ICMJE
MLA
NLM
Adamson, J., & Wu, Q. (2009). Optimizing monoscopic kV fluoro acquisition for prostate intrafraction motion evaluation. Phys Med Biol, 54(1), 117–133. https://doi.org/10.1088/0031-9155/54/1/008
Adamson, Justus, and Qiuwen Wu. “Optimizing monoscopic kV fluoro acquisition for prostate intrafraction motion evaluation.Phys Med Biol 54, no. 1 (January 7, 2009): 117–33. https://doi.org/10.1088/0031-9155/54/1/008.
Adamson, Justus, and Qiuwen Wu. “Optimizing monoscopic kV fluoro acquisition for prostate intrafraction motion evaluation.Phys Med Biol, vol. 54, no. 1, Jan. 2009, pp. 117–33. Pubmed, doi:10.1088/0031-9155/54/1/008.
Adamson J, Wu Q. Optimizing monoscopic kV fluoro acquisition for prostate intrafraction motion evaluation. Phys Med Biol. 2009 Jan 7;54(1):117–133.
Journal cover image

Published In

Phys Med Biol

DOI

ISSN

0031-9155

Publication Date

January 7, 2009

Volume

54

Issue

1

Start / End Page

117 / 133

Location

England

Related Subject Headings

  • Time Factors
  • Sensitivity and Specificity
  • Radiation Dosage
  • Prostate
  • Nuclear Medicine & Medical Imaging
  • Movement
  • Models, Biological
  • Male
  • Magnetic Resonance Imaging
  • Imaging, Three-Dimensional