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Model-Interpolated Gating for Magnetic Resonance Image-Guided Radiation Therapy.

Publication ,  Journal Article
Ginn, JS; O'Connell, D; Thomas, DH; Low, DA; Lamb, JM
Published in: Int J Radiat Oncol Biol Phys
November 15, 2018

PURPOSE: To develop and validate a technique for radiation therapy gating using slow (≤1 frame per second) magnetic resonance imaging (MRI) and a motion model. Proposed uses of the technique include radiation therapy gating using T2-weighted images and conducting additional imaging studies during gated treatments. METHODS AND MATERIALS: The technique uses a physiologically guided breathing motion model to interpolate deformed target position between 2-dimensional (2D) MRI images acquired every 1 to 3 seconds. The model is parameterized by a 1-dimensional respiratory bellows surrogate and is continuously updated with the most recently acquired 2D images. A phantom and 8 volunteers were imaged with a 0.35T MRI-guided radiation therapy system. A balanced steady-state free precession sequence with a 2D frame rate of 3 frames per second was used to evaluate the technique. The accuracy and beam-on positive predictive value (PPV) of the model-based gating decisions were evaluated using the gating decisions derived from imaging as a ground truth. A T2-weighted gating offline proof-of-concept study using a half-Fourier, single-shot, turbo-spin echo sequence is reported. RESULTS: Model-interpolated gating accuracy, beam-on PPV, and median absolute distances between model and image-tracked target centroids were, on average, 98.3%, 98.4%, and 0.33 mm, respectively, in the balanced steady-state free precession phantom studies and 93.7%, 92.1%, and 0.86 mm, respectively, in the volunteer studies. T2 model-interpolated gating in 6 volunteers yielded an average accuracy and PPV of 94.3% and 92.5%, respectively, and the mean absolute median distance between modeled and imaged target centroids was 0.86 mm. CONCLUSIONS: This work demonstrates the concept of model-interpolated gating for MRI-guided radiation therapy. The technique was found to be potentially sufficiently accurate for clinical use. Further development is needed to accommodate out-of-plane motion and the use of an internal MR-based respiratory surrogate.

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Published In

Int J Radiat Oncol Biol Phys

DOI

EISSN

1879-355X

Publication Date

November 15, 2018

Volume

102

Issue

4

Start / End Page

885 / 894

Location

United States

Related Subject Headings

  • Respiration
  • Radiotherapy, Image-Guided
  • Phantoms, Imaging
  • Oncology & Carcinogenesis
  • Movement
  • Magnetic Resonance Imaging
  • Humans
  • 5105 Medical and biological physics
  • 3407 Theoretical and computational chemistry
  • 3211 Oncology and carcinogenesis
 

Citation

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ICMJE
MLA
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Ginn, J. S., O’Connell, D., Thomas, D. H., Low, D. A., & Lamb, J. M. (2018). Model-Interpolated Gating for Magnetic Resonance Image-Guided Radiation Therapy. Int J Radiat Oncol Biol Phys, 102(4), 885–894. https://doi.org/10.1016/j.ijrobp.2018.05.012
Ginn, John S., Dylan O’Connell, David H. Thomas, Daniel A. Low, and James M. Lamb. “Model-Interpolated Gating for Magnetic Resonance Image-Guided Radiation Therapy.Int J Radiat Oncol Biol Phys 102, no. 4 (November 15, 2018): 885–94. https://doi.org/10.1016/j.ijrobp.2018.05.012.
Ginn JS, O’Connell D, Thomas DH, Low DA, Lamb JM. Model-Interpolated Gating for Magnetic Resonance Image-Guided Radiation Therapy. Int J Radiat Oncol Biol Phys. 2018 Nov 15;102(4):885–94.
Ginn, John S., et al. “Model-Interpolated Gating for Magnetic Resonance Image-Guided Radiation Therapy.Int J Radiat Oncol Biol Phys, vol. 102, no. 4, Nov. 2018, pp. 885–94. Pubmed, doi:10.1016/j.ijrobp.2018.05.012.
Ginn JS, O’Connell D, Thomas DH, Low DA, Lamb JM. Model-Interpolated Gating for Magnetic Resonance Image-Guided Radiation Therapy. Int J Radiat Oncol Biol Phys. 2018 Nov 15;102(4):885–894.
Journal cover image

Published In

Int J Radiat Oncol Biol Phys

DOI

EISSN

1879-355X

Publication Date

November 15, 2018

Volume

102

Issue

4

Start / End Page

885 / 894

Location

United States

Related Subject Headings

  • Respiration
  • Radiotherapy, Image-Guided
  • Phantoms, Imaging
  • Oncology & Carcinogenesis
  • Movement
  • Magnetic Resonance Imaging
  • Humans
  • 5105 Medical and biological physics
  • 3407 Theoretical and computational chemistry
  • 3211 Oncology and carcinogenesis