Evaluation of lung tumor motion management in radiation therapy with dynamic MRI

Seyoun Park, Rana Farah, Steven M. Shea, Erik Tryggestad, Russell Hales, Junghoon Lee

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Surrogate-based tumor motion estimation and tracing methods are commonly used in radiotherapy despite the lack of continuous real time 3D tumor and surrogate data. In this study, we propose a method to simultaneously track the tumor and external surrogates with dynamic MRI, which allows us to evaluate their reproducible correlation. Four MRIcompatible fiducials are placed on the patient's chest and upper abdomen, and multi-slice 2D cine MRIs are acquired to capture the lung and whole tumor, followed by two-slice 2D cine MRIs to simultaneously track the tumor and fiducials, all in sagittal orientation. A phase-binned 4D-MRI is first reconstructed from multi-slice MR images using body area as a respiratory surrogate and group-wise registration. The 4D-MRI provides 3D template volumes for different breathing phases. 3D tumor position is calculated by 3D-2D template matching in which 3D tumor templates in 4D-MRI reconstruction and the 2D cine MRIs from the two-slice tracking dataset are registered. 3D trajectories of the external surrogates are derived via matching a 3D geometrical model to the fiducial segmentations on the 2D cine MRIs. We tested our method on five lung cancer patients. Internal target volume from 4D-CT showed average sensitivity of 86.5% compared to the actual tumor motion for 5 min. 3D tumor motion correlated with the external surrogate signal, but showed a noticeable phase mismatch. The 3D tumor trajectory showed significant cycle-to-cycle variation, while the external surrogate was not sensitive enough to capture such variations. Additionally, there was significant phase mismatch between surrogate signals obtained from fiducials at different locations.

Original languageEnglish (US)
Title of host publicationMedical Imaging 2017
Subtitle of host publicationImage-Guided Procedures, Robotic Interventions, and Modeling
PublisherSPIE
Volume10135
ISBN (Electronic)9781510607156
DOIs
StatePublished - 2017
EventMedical Imaging 2017: Image-Guided Procedures, Robotic Interventions, and Modeling - Orlando, United States
Duration: Feb 14 2017Feb 16 2017

Other

OtherMedical Imaging 2017: Image-Guided Procedures, Robotic Interventions, and Modeling
CountryUnited States
CityOrlando
Period2/14/172/16/17

Keywords

  • Dynamic MRI
  • Lung cancer
  • Motion management
  • Radiation therapy

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Radiology Nuclear Medicine and imaging

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  • Cite this

    Park, S., Farah, R., Shea, S. M., Tryggestad, E., Hales, R., & Lee, J. (2017). Evaluation of lung tumor motion management in radiation therapy with dynamic MRI. In Medical Imaging 2017: Image-Guided Procedures, Robotic Interventions, and Modeling (Vol. 10135). [101351R] SPIE. https://doi.org/10.1117/12.2254676