Patterns of Brain Tumor Recurrence Predicted From DTI Tractography - - PowerPoint PPT Presentation

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Patterns of Brain Tumor Recurrence Predicted From DTI Tractography - - PowerPoint PPT Presentation

Patterns of Brain Tumor Recurrence Predicted From DTI Tractography Anitha Priya Krishnan 1 , Isaac Asher 2 , Dave Fuller 2 , Delphine Davis 3 , Paul Okunieff 2 , Walter ODell 1,2 Department of Biomedical Engineering 1 , Radiation Oncology 2 and


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Patterns of Brain Tumor Recurrence Predicted From DTI Tractography

Anitha Priya Krishnan1, Isaac Asher2, Dave Fuller2, Delphine Davis3, Paul Okunieff2, Walter O’Dell1,2

Department of Biomedical Engineering1, Radiation Oncology2 and Imaging Sciences3 University of Rochester Medical Center, Rochester, NY USA 14642

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Stereotactic Radiotherapy (SRT)

Radiation oncologists: 4 - 30mm isotropic

margin for gliomas

Small margin: recurrences Large margin: damage normal tissue

Clinical observation

Recurrence often at the boundary of treatment

margin

Goal:

Develop appropriate anisotropic treatment

margins using Diffusion Tensor Imaging (DTI)

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Goal

Qualitative correlation of paths of

elevated water diffusion along white matter tracts from Tractography with recurrent site.

Hypothesis: paths of elevated water

diffusion along white matter tracts provide a preferred route for migration of cancer cells.

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Migration Along WM Tracts

Migration of cancer cells along WM tracts in

Glioblastoma:

1938 Scherer HJ. 1961 Matsukado et al. 1988 Burger et al. 1989 Johnson et al.

Correlate CT with topographic anatomy and

postmortem MR imaging with neuropathologic findings

Our approach: Correlate White matter tracts from DTI

  • f each patient with recurrent site
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DTI of Glioblastoma

Scalars from DTI (Fractional

Anisotropy and Apparent Diffusion Coefficient)

2003 Price et al [1] 2004 Hein et al [2] 2005 Beppu et al [3]

Vectors from DTI (principal Eigen

vector)

2004 Field et al [4]

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Patient Selection

Category1: distant recurrence

Small island of recurrent tumor in the DTI

dataset acceptable

Category2: local recurrence

close to (within 2 cm) or on the boundary of

the treatment plan

No sign of recurrence in the DTI dataset

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Image Acquisition

GE signa 1.5T MRI scanner EPI sequence, 20 axial slices, voxel

dimensions 0.976×0.976×6 mm

25 diffusion gradient directions, b =

1000, 3 reference (b = 0) scans

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DTI Analysis

Tractography: DTIStudio and FSL (

  • DTIStudio [5]: Fiber Assignment by Continuous

Tracking (FACT)

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DTI Analysis

FSL [6]:

Probabilistic fiber tracking Calculates uncertainty in the fiber direction Can track fibers in gray matter

Fiber probability maps for seed point in optic tract Yellow – high probability, Red – moderate relative probability

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Results: Category 1 (n = 3)

Spot on left horn not treated Tumor growth Primary GBM Fiber tracts passing through: Primary tumor Recurrent site

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Results: Category 1

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Results: Category 2 (n = 4)

Primary Glioma SRS treatment plan Yellow – High probability. Red – Medium relative probability of connection Pretreatment MR T1 Fiber Map from FSL Recurrence tumor Post contrast Axial MR T1 3 months after SRS

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Results: Category 2

Pretreatment MR T1 SRS treatment plan Fibers from primary Post contrast Axial MR T1 3 months after SRS Primary tumor Recurrence tumor

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Results: Category 2

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Conclusions & Future Work

Preliminary results on a small number of

patient datasets suggest that the hypothesis is correct

Future Work

High resolution DTI dataset using 3T MR Improved Fiber analysis Verification with animal models

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References

1.

Price SJ, Burnet NG, Donovan T, et al. Diffusion tensor imaging of brain tumors at 3T: a potential tool for assessing white matter tract invasion? Clin Radiol. 2003; 58: 455-462.

2.

Hein, Patrick A, Eskey, et al. Diffusion-Weighted Imaging in the Follow-up of Treated High-Grade Gliomas: Tumor Recurrence versus Radiation Injury. AJNR Am J Neuroradiol 2004 25: 201-209.

3.

Beppu T, Inoue T, Shitaba Y, et al. Fractional anisotropy value by diffusion tensor magnetic resonance imaging as a predictor of cell density and proliferation activity of glioblastomas. Surg Neurol. 2005; 63(1): 56-61.

4.

Field Aaron, Alexander Andrew. Diffusion Tensor Imaging in cerebral tumor diagnosis and therapy. Top Magn Reson Imaging. 2004 oct; 15 (5): 315-24.

5.

Huang H, Zhang J, van Zijl PC, Mori S. Analysis of noise effects on DTI-based tractography using the brute-force and multi-ROI

  • approach. Magnetic Resonance in Medicine 2004;52(3):559-65.

6.

T.E.J. Behrens, M.W. Woolrich, et al. Characterisation and Propagation of Uncertainty in Diffusion Weighted MR imaging. Magn. Reson Med 2003;50:1077-1088.