simulation of hypoxia pet tracer dynamics based on tumour tissue microsections
DESCRIPTION
Simulation of hypoxia PET tracer dynamics based on tumour tissue microsections. Molecular Imaging in Radiation Oncology Brussels, 18 – 20 March 2010. David Mönnich Section for Biomedical Physics, Radiooncological Clinic, Tübingen. Introduction. Larynx carcinoma, FMISO PET 4 h p.i. - PowerPoint PPT PresentationTRANSCRIPT
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Simulation of hypoxia PET tracer dynamics based on tumour tissue
microsections
Molecular Imaging in Radiation Oncology
Brussels, 18 – 20 March 2010
David MönnichSection for Biomedical Physics, Radiooncological Clinic, Tübingen
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Introduction
Dose distribution can be tailored by IMRT (Dose Painting)
Hypoxia PET imaging with [18F]-FMISO
Dynamic PET imaging: Voxel-wise Time Activity Curves (TACs)
D. Mönnich, MIRO 2010, Brussels 2
Larynx carcinoma,FMISO PET 4 h p.i.
TACs
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Objective
Link PET voxel signals to the underlying tumour microstructure
D. Mönnich, MIRO 2010, Brussels 3
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Creating vascular maps from tumour microsections
Extracted vascular map
Regions with different vascular fractions (VF)
D. Mönnich, MIRO 2010, Brussels 4
Courtesy of E. Troost, UMC Nijmegen
Blue: Endothelium Red: Proliferation Green: Hypoxia
3.9
mm
Low VF (1.0%)
Interm. VF (3.4%)
High VF (14.5%)
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Model & Simulation Method
D. Mönnich, MIRO 2010, Brussels 5
Solve oxygen reaction-diffusion equation
Static oxygen distribution
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Model & Simulation Method
D. Mönnich, MIRO 2010, Brussels 6
Solve oxygen reaction-diffusion equation
Increase
Necrotic regime
Static oxygen distribution
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Model & Simulation Method
D. Mönnich, MIRO 2010, Brussels 7
Solve oxygen reaction-diffusion equation Solve FMISO
reaction-diffusion equation
Increase
Necrotic regime
Static oxygen distribution
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Tracer supply to hypoxic areas is diffusion limited
FMISO binding is not hypoxia specific in the first 15 minutes
Results
D. Mönnich, MIRO 2010, Brussels 8
3.8
mm
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Tracer supply to hypoxic areas is diffusion limited
FMISO binding is not hypoxia specific in the first 15 minutes
Results
D. Mönnich, MIRO 2010, Brussels 9
3.8
mm
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Results
TACs from differently perfused regions
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Results
TACs from differently perfused regions
Different microstructure can lead to similar late signal
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Summary and conclusion
Summary● FMISO supply to hypoxic regions is limited by molecular
diffusion speed on relevant time scales● Different tissue microstructure can lead to similar voxel
activitiy in static PET images
Conclusion● Dose painting using static images might omit hazardous
tumour regions● Imaging of perfusion seems necessary in addition to
static hypoxia imaging
D. Mönnich, MIRO 2010, Brussels 12